Chem/Phys (4)

According to the photoelectric effect, an electron can be ejected from a material by a photon when ________.

The photon energy, hf, is greater than the work function of the material. (electronic structure)

Nuclear binding energy vs electron binding energy:

*binding energy most commonly refers to nuclear binding energy (the energy that holds nucleons together) *binding energy could also refer to the electron binding energy. This is not commonly used bc the electron binding energy is more commonly referred to as ionization energy (atomic nucleus)

Give the equation for the force of kinetic friction. Is there an equation for the force of static friction?

*force of kinetic friction: Ffkinetic=µkineticFn *There is no equation for the force of static friction. There is only an equation for the maximum force of static friction Ffstaticmax=µstaticFn

A glass sphere of specific gravity 2.5 and volume 10⁻³m³ is completely submerged in a large container of water. What is the apparent weight of the sphere while immersed?

*fully submerged means Vsubmerged=V *First, specific gravity= density of sphere/density of water → 2.5=⍴sphere//1000kg/m³ → 2500=⍴sphere *second, the true weight of the glass sphere is, w=⍴Vg → w= (2500)(10⁻³)(10) → 25N *third, find the buoyant force, Fbuoyant=⍴fluidVsubmergedg → (1000)(10⁻³)(10) → 10N *so, the apparent weight of the sphere is, wapparent=w-Fbuoyancy → wapparent= 25N-10N → 15N (fluids)

Molarity vs Molality and Mass vs Molar Mass:

*molarity, M, mol/L *molality, m, mol/kg *mass, kg *molar mass, g/mol

Alpha particle vs beta particle vs gamma ray:

-alpha particle: weakest form of radiation. Can be stopped by a sheet of paper. It is essentially a relatively low speed helium nucleus -beta particle: more energy than an alpha particle. Can be stopped by aluminum foil. It is a high speed electron -gamma ray: strongest form of radiation. It is a high energy EM wave. Can be stopped by a thick layer of lead or concrete. (atomic nucleus)

Gamma decay:

-an e- relaxing to its ground state emits energy in the form of one or more photons of electromagnetic radiation. These photons are called gamma photons. They are very high in energy. -gamma decay usually happens after a nucleus has undergone alpha or any type of beta decay. The excited energy state relaxes to ground state. -no change in the parent's atomic number (same number of p+) -no change in the parent's mass number (same number of n + p+) (atomic nucleus)

Liquid:

-atoms/molecules move about, but are close together and bound by intermolecular forces -density is constant -medium kinetic energy -medium entropy -hard to compress -flows to fill a container

Molar enthalpy vs enthalpy:

-molar enthalpy is ΔH in kJ/mol -enthalpy is ΔH in kJ

Scalar quantities vs vector quantities:

-scalar quantities: have only magnitude, no direction. Includes length, time, mass, area, volume, speed, density, pressure, temperature, energy, entropy, work, power -vector quantities: have both magnitude and direction. Includes displacement, velocity, acceleration, force (lift, drag, weight), momentum (translational motion)

What can a reduction potential tell you about oxidizing and reducing agents?

-the more negative the reduction potential, the weaker the reactant is as an oxidizing agent, and the stronger the product is as a reducing agent -the more positive the reduction potential, the stronger the reactant is as an oxidizing agent, and the weaker the product is as a reducing agent Ex: Pb²⁺ + 2e- → Pb, has a standard potential of -0.13V Al³⁺ +3e- → Al, has a standard potential of -1.67V *since Al³⁺ has a large negative reduction potential, the product, Al, is a good reducing agent (wants to give e- to something else) (electrochemistry)

Thermochemistry vs electrochemistry:

-thermochemistry= a branch of thermodynamics which focuses on the study of heat given off or absorbed in a chemical reaction *thermodynamics= the study of the relationship between heat, work, and other forms of energy -electrochemistry= the study of chemical processes that cause electrons to move. (electrochemistry)

Faraday's law of electrolysis:

-used w electrolytic cells to determine the amounts of elements deposited (or gas liberated) at the two electrodes. -the amount of substance produced at each electrode is directly proportional to the quantity of charge flowing through the cell. -current= The flow of charge in a circuit. How much charge is passing a certain point per sec. *measured in Amps, (coulombs of charge per second) I=q/t, where I is the current, q is the total charge, and t is time in seconds -faraday's constant= the magnitude of charge that 1 mole of electrons has. 1 mole of electrons always has a charge of 96,500 C/mol, this is the faraday constant. F=q/n, where q is total charge, n is total moles ***Equation to remember, relates current, time, moles of electrons, and faraday's constant: It = nF (current)(time) = (moles of e-)(Faraday's constant) (electrochemistry)

Whats does a graph of gauge pressure as a function of depth look like? What about a graph of total pressure as a function of depth in the same fluid?

1)Gauge pressure vs depth: directly proportional; when depth=0, pressure=0 2)Total pressure vs depth: not directly proportional (does not start at the origin). Graph is parallel to "gauge pressure vs depth line." When depth=0, total pressure ≠ 0 bc you still have Patm (fluids)

Times tables, 8:

8x1 = 8 8x2 = 16 8x3 = 24 8x4 = 32 8x5 = 40 8x6 = 48 8x7 = 56 8x8 = 64 8x9 = 72 8x10 = 80 8x11 = 88 8x12 = 96 8x13 = 104 8x14 = 112 8x15 = 120 *And 8²=64

The magnification equation:

allows you to answer questions such as: Is the image upright or it is inverted? How tall is the image (compared to the object)? m= -i/o = h'/h *m is the magnification factor. If m is positive, the image is upright. If m is negative, the image is inverted. *i is the image's distance from the mirror i is positive if the image is real i is negative if the image is virtual *o is the object's distance from the mirror (always a positive value) *h' is height of the image and h is height of the object. Multiplying the height of the object, h, by m gives you the height of the image, h' (geometrical optics)

Dielectric:

nonconducting material. *inserting a dielectric between the plates of a capacitor always increases the capacitance. It does this by either increasing Q (if V is constant) or decreasing V (if Q is constant). Remember, C=Q/V. The capacitance of a parallel-plate capacitor with a dielectric is given by: Cwithdielectric = K Cwithoutdielectric = Kɛ A/d, where K is the dielectric constant, ɛ is the permittivity of free space (8.85x10⁻¹² F/m), A is the area of each plate, and d is distance between the plates. Capacitance has units of farad, F. Coulomb per Volt. *K is the dielectric constant of the insulating material, its value varies for diff materials. The smallest value of K is air, (no dielectric), where K=1. The value of K is never less than 1, which is the reason why dielectrics always increase capacitance (Circuit Elements)

Strain:

the deformation of the object in the direction of the applied stress force divided by the original length. Expressed by: strain=ΔL/Li (fluids)

Ionization energy:

the minimum amount of energy required to remove the outermost e- from an atom in its gaseous state. PERIODIC TREND= *ionization energy decreases as you go down a group bc of increasing radii *ionization energy increases as you go across a row bc of decreasing radii **highest ionization energy = noble gases, He > Ne > Ar **lowest ionization energy = alkali metals, Li, Na, K, etc **local maxima occurs for filled subshells and half-filled p subshells (high ionization energy/hard to remove a valence e- bc half-filled/filled subshells are stable) -as Felectrostatic and/or effective nuclear charge increases, removing additional electrons require more energy -first ionization energy (IE₁)= the energy needed to knock off the first valence e- -second ionization energy (IE₂)= the energy needed to knock off the second valence e- -the second ionization energy is always higher than the first ionization energy (usually a lot higher) -alkali metals and H = the first ionization energy is very low. The second ionization energy is much higher -alkaline earth metals = the first ionization energy is low. The second ionization energy is also low (periodic table; group and row)

Quantum physics:

the physics associated with discrete values and changes in the values of such quantities; that is, their quantization. For ex, only charges that are integer multiples of the elementary charge e=1.6x10⁻¹⁹ coulombs will ever be observed, bc you can't have half a proton or two-thirds of an electron. Thus, charge is quantized! *quantum physics also looks at the wave-particle duality of light, since photons are quantized (atomic nucleus)

Stress:

the pressure exerted on an object, expressed by: stress=F/A -similar to pressure, but stress and pressure are not he same bc w stress, the forces do not have to be perpendicular to the area over which it acts (fluids)

What is the Bernoulli or Venturi effect?

the pressure of a stream of fluid is reduced as the flow speed is increased

Radioactive decay:

unstable nuclei are radioactive. Bc of this, they undergo a transformation which makes them more stable. They lower their energy and/or altering the number/ratio of p+ and/or n. This process is called radioactive decay. *There are three types: -alpha decay -beta decay -gamma decay (atomic nucleus)

Longitudinal wave:

wave displacement is parallel to the direction of motion. -includes SOUND, pressure waves, and earthquakes -ex, you hold a slinky on the left end and move it left and right. Energy will be transported through the slinky from left to right. The individual coils of the slinky will move left and right in a wave motion. Wave displacement (left and right) is parallel to direction of motion (left to right) (periodic motion)

Of the following, the element that possesses properties of both metals and nonmetals is A)Si B)Al C)Zn D)Hg

*answer=A. Elements that possess quantities of both metals and nonmetals are metalloids. (the periodic table; electronic structure)

A mixture of neon and nitrogen contains 0.5mol Ne(g) and 2mol N2(g). If the total pressure is 20atm, what is the partial pressure of the neon?

*first, the mole fraction for Ne is: X= .5/(.5+2) → .5/2.5 → ⅕ is the mole fraction for Ne *so, Pneon=(Xneon)(Ptotal) → Pneon=(⅕)(20atm) → 4atm (gas phase)

Solid:

-atoms/molecules vibrate about a fixed position. Held in place by intermolecular interactions -density is constant -low kinetic energy -low entropy -hard to compress -does not flow to fill a container

What is a hydride ion?

A hydride ion is an anion of hydrogen, H-, consisting of 1p+, 0n, 2e-

List the most electronegative elements in order:

FONClBrISCH -pronounced "fawn-cull-brish" -lists the elements in order from most electronegative (F) to the least electronegative (H). (periodic table; group and row)

Crystallization:

Freezing. Going from a liquid → solid

Liquids are incompressible. What does this mean?

It's density remains constant (fluids)

Curved mirrors:

a mirror with a curved reflecting surface. Also called "spherical mirrors" bc near the center of the mirror, the surface is spherical Two types of curved mirrors: 1)concave mirror= bulging inward; curve bulges away from the light it reflects. Appears like the entrance to a "cave" from the point of view of the object. Concave mirrors can focus light, so its converging. Examples of concave mirror: front of a spoon, cosmetic mirrors, used for magnification in telescopes 2)convex mirror= bulging outward; curve bulges toward the light it reflects. Convex mirrors can't focus light, so its diverging. Examples of convex mirrors: back of a spoon, passenger side rear-view mirror of a car (geometrical optics)

Emulsion:

a mixture of two or more liquids that are normally unmixable or unblendable. One liquid is present as droplets, of microscopic size, distributed throughout the other. For ex, if you shake water and oil vigorously, you can get an emulsion, which is a temporary colloid.

Diffusion:

random molecular motion, causing a substance to move from an area of higher concentration to an area of lower concentration (diffusion down its concentration gradient) (gas phase)

Motion on an inclined plane:

the Fw acts straight downward from the object on the incline plane. Thus, the Fw is divided into two components, Fwx= mgsin(theta) and Fwy= mgcos(theta) *another way to say this, the force due to gravity acting parallel to the inclined plane= mgsin(theta). And the force due to gravity acting perpendicular to the inclined plane= mgcos(theta). The Fwy is also called the 'normal component of gravity.' The Fn = Fwy → Fn = mgcos(theta), we know this bc the object is not crashing through the surface of the inclined plane. -a non-moving object sitting on an inclined plane: the normal component of gravity = normal force the parallel component of gravity = static friction -an object moving down an inclined plane at constant velocity: the parallel component of gravity = kinetic friction. *constant velocity = no acceleration = no net force -an object that begins to slip on the inclined plane, the parallel component of gravity > static friction -an object that accelerates down the inclined plane, the parallel component of gravity > kinetic friction -when you push an object up an inclined plane, you need to overcome both the parallel component of gravity and friction (Force)

Specific Gravity:

the density of something compared to water, expressed by: specific gravity = density of substance x/density of water -the density of liquid water is 1g/mL = 1g/cm^3 = 1kg/L = 1000 kg/m^3 -the specific gravity of water is 1 -Ex, density of lead = 11g/cm^3. So, the specific gravity of lead = 11g/cm^3 // 1g/cm^3 → 11 **specific gravity is unitless (fluids)

Elastic limit:

the maximum stress something can handle before it breaks or becomes permanently deformed (fluids)

Infrasound:

vibrations whose frequency is too low to hear (sound)

How does structural changes affect absorption when using indicators?

*Changes to chemical structure can lead to changes in absorption. *H-indicator <--> H+ + Indicator- *H-indicator absorbs at a certain wavelength and is of one color. *Indicator- absorbs at a different wavelength so is of a different color. *At low pH, high [H+], H-indicator and its color will predominate. *At high pH, low [H+], indicator- and its color will predominate. *At neutral pH, both H-indicator and indicator- will co-exist in an equilibrium, so the color will be a mixture of the two. (molecular structure and absorption spectra)

A particle of mass m and charge q is placed at a point where the electric field is E. If the particle is released from rest, find its initial acceleration, a.

*F=ma → a=F/m *Felectricalonq=qE Answer: a=qE/m -notice that if q is negative, then F and acceleration will be directed opposite to the electric field, E. Also, the question only asked for initial acceleration bc once the particle starts moving, it will move through locations where the electric field is different, so the force on the particle will change and so will its acceleration. If a region contains a uniform electric field, then the electrostatic force and the particle's acceleration will be uniform, thus the Big 5 kinematics can then be used to find final velocity, etc. In addition, the formula for work, W=Fdcosθ, can be used to determine the work done by or against an electrostatic force *a parallel plate capacitor creates an electric field that is uniform (Electrostatics)

An astronaut (total mass, body + suit + equipment = 100kg) is floating at rest in deep space near her ship, when she notices that the cord that's supposed to keep her connected to the ship has broken. She reaches into her pocket, finds a metal tool of mass 1kg and throws it out into space w a velocity of 10m/s, directly away from the ship. If she's 5m away from the ship, how long will it take her to reach it?

*First, consider the astronaut and the metal tool as the system. Initially both are at rest, so their total momentum=0. Bc the law of conservation of momentum says that Δpsystem = 0, we know that after the astronaut throws the tool, the total momentum of the system (astronaut + tool) will still be zero. (mass of astronaut)(velocity' of astronaut) = -(mass of tool)(velocity' of tool) So, velocity' of astronaut= -(mass of tool)(velocity' of tool)//mass of astronaut → -(1kg)(-10m/s)/100kg → .1m/s=velocity of astronaut note, here we are calling away from the ship the negative direction *Second, v=Δx/Δt → Δt=Δx/v → Δt=5m/.1 → 50seconds (Equilibrium)

A string is tied around a rock of mass 0.2kg, and the rock is then whireled at a constant speed v in a horizontal circle of radius 0.4m. If sinθ=0.4 and cosθ=0.9, what's v?

*First, draw a pic. Break the Ft into its x and y components. Fty= Ftsinθ Ftx= Ftcosθ *Look at the vertical components: Since the rock is not moving vertically, the net vertical force must be zero. So, Fty = mg → Ftsinθ=mg. From this, we can find the Ft of the string on the rock Ft=mg/sinθ → (.2kg)(10)/.4 → 5N is the force of tension in the string *Look at the horizontal components: here, the centripetal force is provided by the horizontal component of tension, Ftx. Ftx = mv²/r → Ftcosθ = mv²/r → v = √(rFtcosθ/m) → √(.4m)(5N)(.9)/.2kg → 3m/s = v (Force)

A young child is sliding down a hill at an incline of 30 degrees on a sled w total combined mass of 10kg. If the coefficient of friction between the hill and the sled is 0.3 and the length of the hill is 50m, how much work has been done by gravity when the child reaches the bottom?

*First, draw a pic. Fgx = mgsinθ and Fgy = mgcosθ. Here, we don't care about y components. The sled is not falling through the earth. We only care about x components. *we know W=mgcosθ, and since the force is parallel to displacement, we have W=Fd *plugging in Fgx, we get W=mgsinθd → W= (10)(10)sin(30)(50m) → (100)(½)(50) → 2500J= W (Work)

Explain electric fields and magnetic fields:

*If a charge is at rest, it produces an electric field in the surrounding space, with field lines pointing outwards from a positive source charge, Q, and inwards towards a negative source charge, -Q. If this charge were to move, the electric field is now a magnetic field. The magnetic field always creates a closed loop, going from the north pole to south pole. KEY: electric fields are created by electric charges; magnetic fields are created by moving electric charges. Understanding Quantum Mechanics: -particles w electric charge are tiny magnets. So, electrons and protons are tiny magnets. Protons are very very tiny magnets (have almost no effect). Electrons are the magnets we care about. Electrons orbiting around the nucleus in a given shell produce magnetic fields. -magnetic fields can exert forces on other things -normally, the net magnetic field of an atom is zero (bc movement of electrons around the nucleus and each magnetic field produced by an individual electron cancels out). This occurs when atoms have all their valence e- paired. -if an atom has a half-filled shell, an atom can produce a magnetic field. For ex, N, Ni, Co, Fe, Mn, and Cr all have half-filled valence shells, and thus can produce a magnetic field. -just bc an individual atom is magnetic doesn't mean that an object, (made up of millions of a certain atom), is going to be magnetic. For ex, Cr is a magnetic atom, but a non-magnetic solid object -when atoms get together to make an object, their magnetic field can all align (ferromagnetic); or they can all cancel out (anti-ferromagnetic); or they can have no organization at all (paramagnetic). note: atoms with filled valence shells, like Ne, produce no magnetic field (diamagnetic) -additionally, an object can have different "domains." One part of an object may have magnetic fields aligned a certain way, while another part of the object has magnetic fields aligned a different way -in order for something to be a magnet, it must: have domains within the object aligned the same way; and each electron must have a half-filled valence shell so it can produce a magnetic field (Magnetism)

______ can be used as an oxidizing agent in many oxidation-reduction titrations. ______ can be used as a reducing agent in many oxidation-reduction titrations.

*Iodine can be used as an oxidizing agent in many oxidation-reduction titrations Ared + I₂ → Aox + 2I- *iodide can be used as a reducing agent in many oxidation-reduction titrations Aox + 2I- → Ared + I2 Tred + I₂ → Tox + 2I- If a standard iodine solution is used as a titrant for an oxidizable analyte, the technique is iodimetry. If an excess of iodide is used to quantitatively reduce a chemical species while simultaneously forming iodine, and if the iodine is subsequently titrated with thiosulfate, the technique is iodometry. Iodometry is an example of an indirect determination since a product of a preliminary reaction is titrated.

A red photon and a blue photon both strike a piece of an unknown material at the same acute angle of incidence. Any of the following could happen EXCEPT A) the blue photon ejects an electron but the red photon does not B) the blue photon passes through the material at a faster speed than does the red photon C) the blue photon is reflected while the red photon is transmitted D) both photons eject electrons from the material

*Since blue light is higher frequency/more energetic than red light, it is more likely to eject an electron. So, choices A and D consistent *with dispersion, the blue light experiences a higher index of refraction than does red light when it moves through a material. This means that blue light is more likely to undergo total internal reflection when it strikes the interface between two materials than red light. So, choice C is consistent. Answer= B, bc a higher index of refraction for blue light means that the photon will travel slower than the red one (electronic structure)

In a laboratory experiment, Chamber A holds a mixture of four gases: 1 mole of each of chlorine, fluorine, nitrogen, and carbon dioxide. A tiny hole is made in the side of the chamber, and the gases are allowed to effuse from Chamber A into an empty container. When 2 moles of gas have escaped, which gas will have the greatest mole fraction in Chamber A? A) Cl2 B) F2 C) N2 D) CO2

*The gas w the greatest mole fraction remaining in Chamber A will be the gas w the slowest rate of effusion. This is the gas w the highest MW. Of the gases, Cl2 has the greatest MW, so it will have the greatest mole fraction in Chamber A. (gas phase)

Atomic and ionic radius:

*an atoms electron cloud represents almost all of its volume 1)Atomic radius: -As you fill to the next shell, (ex, Ne to Na), the effective nuclear charge decreases. Felectrostatic decreases, and atomic size increases -as you go down a group, (ex, Na to K), effective nuclear charge stays the same. The Felectrostatic decreases (due to increasing r^2), causing an increase in size -going across the periodic table means filling up the same shell (by going through subshells). As you fill up a shell, the effective nuclear charge and Felectrostatic increases. The atom becomes more compact; decreasing atomic size PERIODIC TRENDS: -atomic size increases as you go down a group -atomic size decreases as you across a row *largest radius= elements w a single e- in their valence shell, for ex, K > Na > Li *smallest radius= elements w a filled valence shell, for ex, Kr > Ar > Ne > He -atomic sizes may overlap is you zigzag on the periodic table 2) Ionic radius: adding or removing electrons, how this affects the radius -adding an electron, creating an anion= valence e- repulsion increases, ionic radius increases; Felectrostatic decreases -removing an electron, creating a cation= valence e- repulsion decreases, ionic radius decreases; Felectrostatic increases *the ionic radius increases with increasing negative charge (lower Felectrostatic) *so, in terms of radius, we have: anion radius > neutral-atom radius > cation radius X- > X > X+ (periodic table; group and row)

A capacitor is charged by a battery and then, while its still connected to its voltage source, a dielectric is inserted between the plates. What happens?

*dielectrics increase C by a factor of K *by using C=Q/V, Q increases while V remains constant *Q increases by a factor of K *V stays the same *E stays the same **since Q is increasing, in PE=1/2QV, PE also increases by a factor of K (Circuit Elements)

A capacitor is charged by a battery and then disconnected from it. What happens if we then insert a dielectric between the plates?

*dielectrics increase C by a factor of K *by using C=Q/V, V decreases while Q remains constant *V decreases by a factor of K *E decreases by a factor of K **the electric field strength, E, decreases. The dielectric is an insulator, so although the field between the plates won't move any free electrons through the material, it will polarize the molecules. That is, the electric field will create tiny dipole moments in the molecules of the insulator, w the slightly negative ends closer to the positive plate and the slightly positive ends closer to the negative plate. These new induced charges create a small electric field, Einduced, which points in the opposite direction from the electric field created by the charged capacitor plates, (bc electric fields always point from positive to negative source charges). Essentially, in V=Ed, the E decreases, thus V also decreases. Also, in PE=1/2QV, since V decreases, PE also decreases. (Circuit Elements)

Two charges, q1=-2x10⁻⁶ C and q2=+5x10⁻⁶ C, are separated by a distance of 10cm. Describe the electrical force between these particles.

*first, 10cm → 1x10⁻¹ m *using Coulomb's Law: Felectrical = k |q1q2| /r² → (9x10⁹ Nᐧm²/C²) (2x10⁻⁶ C)(5x10⁻⁶ C) / (10^-1m)^2 → 90x10⁻³/(10⁻¹ m)² → 90x10⁻³/10⁻² → 90x10⁻¹ → 9N *since the charges have opposite signs, (one is positive and one is negative), the force is attractive. Each charge feels a 9N force toward the other. **this is a good math example with exponents (Electrostatics)

The charge on a parallel-plate capacitor is 4x10^-6 C. if the distance between the plates is 2mm and the capacitance is 1µF, what's the strength of the electric field between the plates?

*first, Q=CV → V=Q/C → V=(4x10⁻⁶ C) /(1x10⁻⁶ F) → 4V *now, V=Ed → 4V= E/(2x10⁻³ m) → 2000 V/m = E (Circuit Elements)

Consider the following reaction, 2ZnS + 3O₂ → 2ZnO + 2SO₂. If 97.5g of zinc sulfide undergoes this reaction w 32g of oxygen gas, what will be the limiting reagent?

*first, convert everything to moles: MW of ZnS is 98g/mol → 1mol MW of O2 is 32g/mol → 1mol -we see that we're starting out with one mol of each. *now, use stoichiometry. Divide the moles by the stoichiometric coefficient of the species: 1mol/2 → 0.5 for ZnS 1mol/3 → 0.333 for O2 *now compare the values. 0.333 is smaller. So O2 is the limiting reactant

A block of mass m attached to a spring w constant k oscillates horizontally on a frictionless surface w amplitude A. In which case does the spring do more work, moving the mass from x=A to x=A/2 or from x=A/2 to x=0?

*first, draw a picture. In both cases, the spring force and displacement are in the same direction. Thus, positive work is being done by the spring. Since the force is not constant, we can't use W=Fdcosθ. Instead, work done by the spring is given by: W= -ΔPE = -(PEfinal - PEinitial) *moving from x=A to x=A/2, we have: W= -(½ k(A/2)² - ½ kA²) → 3/8kA² *moving from x=A/2 to x=0, we have: W= -(½ k(0)² - ½ k(A/2)²) → 1/8kA² **notice that even though the distance traveled is the same in each case, the average force exerted by the spring is greater from x=A to x=A/2 than it is from x=A/2 to x=0, and therefore the work done by the spring is also greater (periodic motion)

Within a metal wire, 5x10¹⁷ conduction electrons drift past a certain point in 4 seconds. What is the magnitude of the current?

*first, the magnitude of the charge that passes a certain point in 4sec is, Q=(5x10¹⁷)(1.6x10⁻¹⁹C) → 8x10⁻² C *so, the current is, I=Q/t → I = 8x10⁻² C/4seconds → 0.02A (Circuit Elements)

If a charged particle's velocity, v, is perpendicular to the magnetic field lines, B, what happens?

*if two things are perpendicular, they are at a 90 degree angle to each other *when a particle's velocity and the magnetic field are at a 90 degree angle to each other, the particle experiences the greatest force *the charged particle will undergo uniform circular motion, with the magnetic force providing the centripetal force. This is expressed by: F = qvB = mv²/r *you are setting the electromagnetic force equal to the centripetal force, which maintains the orbit. Using this equation, you can solve for whatever the question asks you (Magnetism)

What happens when you have a neutral conductor and your bring a positive charge, +Q, nearby without touching it? What happens when you do the same thing w a neutral insulator?

*if you have a neutral conductor, like a metal, and you place it near a positive charge, the free electrons in the conductor will move towards the +Q, leaving one side of the conductor negatively charged and the other side of the conductor positively charged. So, even though the conductor as a whole is electrically neutral, the separation of charges induced by the presence of +Q will create a force of electrical attraction between them *if you have a neutral insulator, like glass, and you place it near a positive charge, +Q, even though there are no free electrons to move around, the atoms which make up the insulator will still become polarized. That is, their electrons will feel a tug toward +Q, causing the atoms to develop a partial negative charge (towards Q+), and a partial positive charge (away from +Q). The effect isn't as dramatic as the movement of free electrons, but the polarization is still enough to cause an electrical attraction. (Electrostatics)

A charge q= -8nC is moved from a position that's 10cm from a charge Q= +2µC to a position that's 20cm away. What is the change in its electrical potential energy?

*let A be the initial point and B the final point **first, find the change in electrical potential: Δɸ= ɸpointb - ɸpointa → kQ/r - kQ/r → kQ(1/radiusatb - 1/radiusata) → (9x10⁹ Nᐧm²/C²)(2x10⁻⁶ C) (1/.2m - 1/.1m) → -9x10⁴ V **Second, find the change in potential energy of the charge q: ΔPEelectric = qΔɸ → (-8x10⁻⁹ C)(-9x10⁴ V) → 7.2x10⁻⁴ J (Electrostatics)

Metals vs Non-metals chemical properties:

*metals chemical properties: -likes to lose e- to gain a positive oxidation state (good reducing agent) -lower electronegativity; partially positive in a covalent bond w a non-metal -forms basic oxides (Na2O or MgO) *non-metals chemical properties: -likes to gain e- to form a negative oxidation state (good oxidizing agent) -higher electronegativity; partially negative in a covalent bond w a metal -forms acidic oxides (SO3 or CO2) (the periodic table; electronic structure)

Metals vs Non-metal physical properties:

*metals physical properties: -good conductor of heat and electricity -malleable/ductile/soft, luster/glossy/reflective surface -solid at room temp (except Hg) *non-metals physical properties: -poor conductor of heat and electricity -Brittle if solid (hard, but able to break/shatter easily) and without luster. -Solid, liquid, or gas at room temp. (the periodic table; electronic structure)

Which has more gravitational PE: an object of mass 2kg at a height of 50m, or an object of mass 50kg at a height of 2m? (set PEgrav=0 at the ground for both objects)

*object 1, PE=mgh → PE=(2kg)(10)(50m) → 1000J *object 2, PE-mgh → PE=(50kg)(10)(2m) → 1000J **therefore, the two objects have the same gravitational PE relative to the ground (energy of point object systems)

Explain the periodic table and how it is organized:

*organization by across vs down: -period/row= going across -family/column/group = going down *organization by blocks= -s-block= group I group II -p-block= group IIIA to group VIIIA -d-block= transition metals -f-block= lanthanides and actinides *organization by metal vs nonmetal: -metals= everything to the left of metalloids. Does not include H *most elements are metals -nonmetal= everything to the right of the metalloids, including H -metalloid= Diagonal line from B to Po. B (boron), Si (silicone), As (arsenic), Te (tellurium), Ge (germanium), Sb (antimony), Po (polonium). NOTE: Po is considered both a metalloid and a metal *organized by family/column/group characteristics: -group 1= alkali metals -group 2= alkaline earth metals -group 3 to group 12= transition metals -group 7= halogens (most reactive halogen is F) -group 8= noble gases (the periodic table; electronic structure)

How much positive charge is contained in 1 mole of carbon atoms? How much negative charge? What is the total charge?

*positive charge: every atom of carbon contains 6 protons, so the amount of positive charge in one carbon atom is q=+6e. Therefore, if NA denotes Avogadro's number, the total positive charge in 1 mole of carbon atoms is, Q=(NA)(q+) → Q= (6.02x10²³)(6)(1.6x10⁻¹⁹ C) → 6x10⁵C *negative charge: every neutral carbon atom also contains 6 electrons, so the amount of negative charge in one carbon is q=-6e. So, total negative charge in 1 mole of carbon atoms is, Q=(NA)(q-) → Q=(6.02x10²³)(6)(-1.6x10⁻¹⁹ C) → -6x10⁵C *total charge on the carbon atom, Q+ + Q- = zero (Electrostatics)

An object is placed 40cm in front of a convex mirror w a radius of curvature of -60cm. Locate and describe the image.

*r= -60cm, so f=1/2r → f= -30cm *o=40cm *use the mirror equation, 1/o + 1/i = 1/f → 1/40 + 1/i = 1/-30 → 1/-30 - 1/40 = 1/i → -4/120 - 3/120 → -7/120 → -120/7 cm =i *since i is negative, the image is virtual and it's located 120/7cm (app 17cm) from the mirror on the opposite side of the mirror from the object. And using m=-i/o → m= -(-120/7)/40 → 3/7. We know the image is 3/7 times the height of the object and upright. (geometrical optics)

An object is placed 40cm in front of a concave mirror w a radius of curvature of 60cm. Locate and describe the image.

*r=60, so f=1/2r → f=30cm *o=40cm *use the mirror equation, 1/o + 1/i = 1/f → 1/40cm + 1/i = 1/30cm → 1/30 - 1/40 = 1/i → 4/120 - 3/120 → 1/120 → 120cm = i *since i is positive, the image is real and it's located 120cm from the mirror on the same side of the mirror as the object. And using m=-i/o → m= -(120cm)/(40cm) → -3. We know the image is 3 times the height of the object and inverted. (geometrical optics)

A positive charge, +q, is placed in the center of an electric dipole. Describe the direction of the resulting electric force on the charge. Do the same for a negative charge, -q, placed at the same point.

*remember, F=qE **the Felectrostatic on the positive charge, +q, is in the same direction as the electric field, E **the Felectostatic on the negative charge, -q, is in the opposite direction as the electric field, E (Electrostatics)

A speaker emitting a sound w a constant frequency approaches a detector. Which of the following wave characteristics will have a greater value at the detector than at the sources? A)frequency B)wavelength C)speed

*since source and detector are moving closer, detected frequency will be higher. *since source is moving and detector is stationary, velocity is constant. So, frequency increases, wavelength decreases, velocity does not change v=ƛf Answer= A, the frequency will have a greater value (sound)

When you pet your cat, you rub electrons off the cat's fur, which are transferred to your hand. Assuming that you transfer 5x10¹⁰ electrons to your hand, what is the electric charge on your hand? What's the charge on the cat?

*since you have gained electrons, the electric charge on your hand is: (5x10^10)(-1.6x10⁻¹⁹ C) → -8x10⁻⁹ *since your cat has lost electrons, the electric charge on your cat is: (5x10¹⁰)(1.6x10⁻¹⁹ C) → +8x10⁻⁹ *notice that the net charge before and after petting the cat is zero. All you've done is transfer charge. (Electrostatics)

A person listening to music on a stereo system experiences a sound level of 70dB. If the volume dial is turned up to increase the intensity by a factor of 500, what sound level would this person hear now? A)97dB B)105dB C)115dB D)120dB

*sound level, 𝜷: 70dB *if intensity, I, had increased by a factor of 100, (10)(10), then sound level would have increased by 10+10=20dB. If intensity, I, had increased by a factor of 1,000, (10)(10)(10), then sound level would would have increased by 10+10+10=30dB. *since intensity is increasing by a factor of 500, which is between 100 and 1000, the sound level must have increased by between 20dB and 30dB. 70dB + 20= 90dB 70dB + 30= 100dB **answer must be between 90 and 100dB. Thus, answer is A. (sound)

The area, A, of each plate of a parallel-plate capacitor satisfies the equation ɛA=10^-10 Fᐧm. If the plates are separated by a distance of 2mm and this space is filled by a sheet of mica with a dielectric constant of 6, what is the capacitance of this capacitor?

*the presence of the mica increases the capacitance by a factor of 6, so: Cwithdielectric = K Cwithoutdielectric = Kɛ A/d → 6(10⁻¹⁰)/(2x10⁻³) → 3x10⁻⁷ F (Circuit Elements)

Primary colors of light vs primary colors of pigments:

*the primary colors of light includes blue, red, and green. Primary colors have additive effects. For ex, if red + green light hits the wall, you will get yellow light. Or, if blue + red + green light hits the wall, you'll get white light. *the primary colors of pigments include cyan, magenta, and yellow. Primary colors of pigments have subtractive effects. "Pigments" remove color by absorbing certain wavelengths of visible light. For ex, a T-shirt appears black in color bc its absorbing red, green, and blue wavelengths (has the pigments cyan, magenta, yellow), producing a black color; no light is reflected off. Or, a T-shirt looks white in color bc it contains no pigments, so red, green, and blue are all reflected off, producing a white color (no visible light is absorbed). (molecular structure and absorption spectra)

If an object is placed very far from a concave mirror, where will the image be formed? A)halfway between the focal point and the mirror B)at the focal point C)at the center of curvature D)at infinity

*use the mirror equation, 1/o + 1/i = 1/f, since the object is placed very far from the mirror, we take plug in infinity for o → 1/∞ = 0. So, we have 1/i = 1/f, which is just i=f. So, the image if formed at the focal point of the mirror, answer is B (geometrical optics)

The big five kinematic equations:

*used only when ACCELERATION IS CONSTANT, also called UNIFORMLY ACCELERATED MOTION. 1)d=½ (v₀ + vf)t → no acceleration 2)vf= v₀ + at → no displacement. Often vi or vf will be zero. 3)d=v₀t + ½ at² → no velocity final 4)d=vft - ½ at² → no velocity initial 5)vf²=v₀² + 2ad → no time (translational motion)

A skier begins at rest at the top of a hill of height 125m. If friction between her skis and the snow is negligible, what will be her speed at the bottom of the hill?

*using the conservation of total mechanical energy, we know that: KE₀ + PE₀ = KEf + PEf → 0 + mgh = 1/2mv² + 0 → vf= √2gh → √(2)(10)(125) → 50m/s=v (energy of point object systems)

Redox titration terminology:

-A= analyte = stuff w the unknown concentration that you want to find out by titration -Aox= analyte that is an oxidizing agent= analyte in its oxidized state (wants e-) -Ared= analyte that is a reducing agent= analyte in its reduced state (wants to get rid of e-) T= titrant = stuff you add drip by drip to determine how much of it is needed to complete the titration Tox= titrant that is an oxidizing agent= titrant in its oxidized state (wants e-) Tred= titrant that is a reducing agent= titrant in its reduced state (wants to get rid of e-) S= standard= something w an accurately known amount or concentration. You use a standard in a reaction to produce a known amount or concentration of I2 Sox= standard that is an oxidizing agent= standard in its oxidized state (wants e-) Sred= standard that is a reducing agent= standard in its reduced state (wants to get rid of e-) X= reactions intermediate= a species that is not present in the net equation of the overall reaction Xox= intermediate that is an oxidizing agent= intermediate in its oxidized state Xred= intermediate that is a reducing agent= intermediate in its reduced state

Alkali metals:

-Group 1, s-block -single valence e-, low ionization energy, very reactive. Wants to lose its e- to achieve empty valence shell -more reactive as you go down bc of increasing radii -reacts w oxygen to form oxides -reacts w water to form hydroxides and released hydrogen, 2X + H2O → 2XOH + H2 -reacts w acids to form salts and releases hydrogen, Na + HCl → NaCl + H2 or NaOH + HCl → NaCl + H2O -most commonly found in the +1 oxidation state (the periodic table; electronic structure)

Other diffraction phenomena:

-Light shining through a pin hole will not appear on the screen as a pin hole. Instead, it will be a diffraction pattern of circular bright and dark bands, with a central bright band. -Light shining past an opaque boundary will not cast a sharp shadow of the boundary on the screen. Instead, fringes of bright and dark bands appear above the boundary. -Light shining past a penny will not cast a completely black shadow. Instead, there will be a central bright spot, as well as patterns of bright and dark rings. (light/electromagnetic radiation)

Doppler effect when you have a moving light source or observer:

-Red shift = frequency decreases = occurs when source and observer is moving away from each other. -Blue shift = frequency increases = occurs when source and observer is moving toward each other. *Observed in astronomy, when stars appear redder/bluer than they really are because they are moving away/toward us. (light/electromagnetic radiation)

Adaptations that help blood flow through the vein at low pressure:

-Respiratory pump: when you inhale, your stomach squeezes on the veins, and your chest sucks on it. -Muscular pump: skeletal muscle squeezes on the veins when you exercise. -When you're scared, smooth muscles around veins constrict and squeezes blood. *increased resistance leads to a slightly increased BP (circulatory system)

Impulse-Momentum theorem:

-We know that F=ma and a=Δv/Δt. So, we can combine these together as F=mΔv/Δt. Multiplying both sides by Δt gives you FΔt=mΔv. If the object's mass remains constant, then we can write it as FΔt=Δ(mv) -Now we see that FΔt is just impulse and Δ(mv) is just momentum. -Thus, the impulse momentum theorem states: J=Δp=Δ(mv)=FΔt -a car traveling down the highway will have a certain momentum. To bring a car to a stop, you can either (1) slam on your break (huge force over a short time) or (2) you can remove your foot from the gas and the car will slowly come to a rolling stop due to friction between the tires and road, (a small force over a long time) (Equilibrium)

Disproportionation:

-a redox rxn in which an element in a single oxidation state reacts to form two diff oxidation states. A species is undergoing both oxidation and reduction. -For ex, 2Cu+ → Cu + Cu²⁺ Here, the Cu is acting as both an oxidizing and reducing agent simultaneously. *the oxidized Cu+ becomes Cu²⁺ (Cu+ gets oxidized) *the reduced Cu+ becomes Cu (Cu+ gets reduced) (electrochemistry)

Process of dissolution in water:

-agitation= stirring or heating can speed up the dissolution process (requires energy) -dissociation= ions dissociate from each other (requires energy) -solvation= ions are surrounded by water molecules (releases energy) Examples: 1)electrolytes dissolve in water. Agitation (endothermic) → dissociation (endothermic) → solvation (exothermic) 2)polar nonelectrolytes dissolve in water Agitation (endothermic) → solvation (exothermic) 3)nonpolar nonelectrolytes do not dissolve in water Agitation (endothermic) → nothing (gas phase)

Galvanic Cells:

-also called a "voltaic cell" -bc a redox rxn involves the transfer of e-, and the flow of e- constitutes an electric current that can do work, we can use a SPONTANEOUS redox rxn to generate an electric current. A device for doing this is called a galvanic (or voltaic) cell. -spontaneous, generates electrical power (ΔG < 0) -total cell voltage, E°, of reaction is positive -anode is negative (wants to get rid of e-) -cathode is positive (wants e-) -electrode= something which conducts electricity. Two types of electrodes: 1) anode: consists of a metal which acts as a reducing agent (itself gets oxidized). The electrons the atoms lose travel through the conducting wire, from the anode to the cathode. Thus, the anode is an "electron source." The anode is negatively charged (wants to get rid of electrons) 2) cathode: consists of a metal which acts as an oxidizing agent (itself gets reduced). The metal accepts electrons from the anode (which flows to it via the conducting wire). Thus, the cathode is an "electron sink." The cathode is positively charged (wants electrons) *e- always flow from the anode to the cathode *oxidation (at the anode) produces e- and shoots out the e- toward the cathode. The cathode receives those e- and uses them for reduction *the anode and cathode are each a "half-cell," connected by a conducting wire and a salt bridge -electrons flow through the conducting wire to/from the electrodes (anode/cathode), while ions flow in the salt bridge. This creates a completed circuit. -the species w the highest oxidation potential/lowest reduction potential (wants to give up electrons!) will be the anode -the species w the highest reduction potential/lowest oxidation potential (wants to accept electrons!) will be the cathode EXAMPLE: -a galvanic cell, the anode is made of zinc (wants to get rid of electrons), and the cathode is made of copper (wants to accepts electrons) -the anode is immersed in a ZnSO₄ soln, and the cathode is immersed in a CuSO₄ soln -each half cell, (the anode and cathode), is connected by a salt bridge containing an aq soln of KNO₃. -when the electrodes are connected by a wire, zinc atoms in the anode are oxidized (Zn → Zn²⁺ + 2e-). The electrons travel through the wire to the cathode. There, the Cu²⁺ ions in soln pick up these electrons and get reduced to copper metal (Cu²⁺ + 2e- → Cu), which accumulates on the copper cathode. -the sulfate ions (SO₄) balance the charge on Zn²⁺, but do not participate in any redox rxn. They are therefore known as SPECTATOR IONS. (remember: the anode is immersed in a ZnSO₄ soln. The cathode is immersed in a CuSO₄ soln). -the Zn2+ ions that remain in soln in the zinc-half cell (here, the anode) attract anions, NO₃⁻, ions from the salt bridge. The cations, K+ ions in the salt bridge, are attracted to the copper-half cell (here, the cathode). *anions from the salt bridge go to the anode *cations from the salt bridge go to the cathode **this movement of ions completes the circuit and allows the current in the wire to continue, (the movement of electrons), until the zinc strip is consumed. (electrochemistry)

Absorption spectrum of hydrogen:

-also called excitation spectra -shows what wavelengths of light are absorbed -the absorption spectra looks like a bright spectrum w dark bands *rainbow background + black lines. Each dark band can be thought of as n=1, n=2, n=3, etc. Red has longest wavelength (lowest energy). Purple has shorter wavelength (higher energy) -the absorption spectrum corresponds to the emission spectrum in pattern Note: the bands correspond to the energy required to excite an electron *absorption, your "absorbing all the bright colors" (way to remember) (atomic nucleus)

Limiting reactants:

-also called limiting reagent, limiting species, etc. -the limiting reagent is the reactant that will get all used up first Ex, what is the limiting reactant for the following reaction 3Xox + Ared → 3Xred + Aox Given: you use 60g of Xox and 63g of Ared Given: the molecular weight of Xox is 2amu, and Ared is 7amu *to solve, the first thing to do is convert everything to moles: 1amu=1g//mol Xox: 2amu=60g//mol → 60g/20amu → 30mol Ared: 7amu=63g//mol → 63g/7amu → 9mol *now, use stoichiometry. Divide the moles by the stoichiometric coefficient of the species: 30mol/3 → 10 for Xox 9mol/1 → 9 for Ared *Now, compare the values. 9 is the smallest. So, Ared is the limiting reactant.

Emission spectrum of hydrogen:

-also called relaxation spectra -shows what wavelengths of light are emitted -the emission spectra looks like a dark spectrum w bright bands *black background + colored lines. The emission spectrum of hydrogen consists of sharp, distinct lines; the emission spectrum shifts to a slightly longer wavelength Note: the bands correspond to the energy emitted when an electron goes back to its ground state *the distinct lines of the emission spectrum prove that electron energy is quantized into energy levels. If electron energy is not quantized, then a continuous spectrum would be observed. (atomic nucleus)

Oxidation state:

-an atom's oxidation state (or oxidation number) is the hypothetical charge that an atom would have if all bonds were ionic. *the oxidation state of an atom in a molecule is the charge it would have if all the e- were completely transferred to the more electronegative element. -It indicates how the atom's "ownership"of its valence e- changes when it forms a compound -a reaction in which the oxidation numbers of any of the reactants change is called an oxidation-reduction (redox) reaction -when an atom loses e-, its oxidation number will increase → this is oxidation -when an atom gains e-, its oxidation number will decrease → this is reduction -Oxidation state ex: with NaCl, the sodium atom will transfer its valence e- to the chlorine atom. The oxidation state of sodium is now +1 (or 1 less e- than it started w). While the chlorine atom now has an oxidation state of -1 (or 1 more e- than it started w). *NaCl is an easy example bc this compound is ionic (complete transfer of e-, no sharing) -oxidation states can be positive, negative or zero -there are certain rules which must be followed when assigning oxidation states (electrochemistry)

Uniform circular motion:

-an object moving in a circular path is said to execute uniform circular motion (UCM) if its speed is constant -this does not mean its velocity is constant. Velocity is a vector, it has both speed and direction. If an object is moving in a circular path, then it's constantly turning and its direction is constantly changing. A changing direction, even at a constant speed, means a changing velocity. An object's velocity vector is always tangent to the circle, in a straight line. So, it is called TANGENTIAL VELOCITY, expressed as: v = rω. Where omega is the ANGULAR VELOCITY, given in radians per second, (rad/s). For an object rotating about an axis, every point on the object has the same angular velocity (the same ω). The tangential velocity of any point is proportional to its distance from the axis of rotation. -By convention, counter-clockwise rotation is positive angular velocity (+ω). While clockwise rotation is negative angular velocity (-ω). -since velocity is changing, the object must be experiencing acceleration. Centripetal acceleration always points toward the center of the circle of motion. It is given by: ac = v²/r *the term "centripetal" is used to describe the acceleration of an object undergoing UCM. -tangential velocity and centripetal acceleration are always perpendicular to each other -if an object is accelerating, then it must be experiencing a force. Remember, the net force on an object and acceleration always point in the same direction. So, centripetal force (the net force) points toward the center of the circle of motion. Centripetal force is the result of the net physical forces, for ex, gravity, friction, etc. Centripetal force is given by: Fc=ma → Fc = mv²/r. Sometimes a negative sign is used for Fc to indicate that the direction of the force is toward the center of the circle -forces that act perpendicular to velocity cannot change the speed http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html (Force)

Unit circle:

-circle w a radius of 1. -radians: a radian gives theta in terms of the subtended arc length/radius or 𝛳 = s/r. A circle contains 2𝜋 radians = 360°. So, dividing both sides by two, we can say that 𝜋 radians = 180°. Ex, an angle whose radian measure is 𝜋/3 is equal to 180°/3 → 60°. Angle radians to memorize: 0° = 0 radians 90° = 𝜋/2 radians 180° = 𝜋 radians 270° = 3𝜋/2 radians 360° = 2𝜋 radians *note: since 𝛳 = s/r, we can find the arc length by s=𝛳r *note: the circumference of a circle is given by: c=2𝜋r *note: the area of a circle is given by: A=𝜋 r² *note: the sector of a circle (the area of a certain portion of a circle), is given by: A'=𝛳A/2𝜋 → A' = ½ 𝛳r² -degrees: gives theta in terms of angle degrees, from 0 to 360. There are 360° in a circle. 180° is a straight line (halfway around the circle). 270° is ¾ around the circle. -cosine and sine: gives the x y graph coordinates on the unit circle. Cos corresponds to your x coordinate. Sin corresponds to your y coordinate. Remember, the unit circle is just a circle w a radius of 1. -tangent: often abbreviated tan, is just sin/cos

Transition metals:

-d-block -high conductivity due to free floating (loosely bound) outer d electrons -in the presence of ligands (when in a chemical complex), the d orbitals become nondegenerate (diff in energy). -electron transitions between nondegenerate d orbitals gives transition metal complexes different colors *The d-orbitals of a free transition metal atom or ion are degenerate (all have the same energy.) However, when transition metals form coordination complexes, the d-orbitals of the metal interact with the electron cloud of the ligands in such a manner that the d-orbitals become non-degenerate (not all having the same energy.) -varied oxidation states, but the oxidation state is always positive (the periodic table; electronic structure)

With uniform circular motion, distinguish between displacement and distance:

-displacement is the shortest, straight line distance between two point on the perimeter of a circle (technically called the chord). -distance is the arc length around the perimeter of a circle -velocity is just displacement/time -speed is just distance/time Some typical cases: -for displacements and distances that approach zero, the instantaneous velocity equals the speed -for a quarter around the circle, (pi/2 radians or 90 degrees), the displacement is just the hypotenuse of a right triangle w the radius as the other two sides. Using a²+b² = c², we can see that the displacement=√(2r²). The distance is just ¼ the circumference. -for half around the circle, the displacement is the diameter. The distance is ½ the circumference -for three quarters around the circle, the displacement is again just the hypotenuse of a right triangle w the radius as the other two sides. But, the direction is different. The distance is ¾ the circumference -completely around the circle, the displacement is zero, which makes the velocity also zero. The distance is the circumference. Note: the velocity is always less than or equal to the speed. The displacement is always less than or equal to the distance. Remember, displacement and velocity are vectors. Distance and speed are not. (Force)

Ground state vs excited state:

-e- absorb only specific, allowed quantities of energy -allowed energies match the energy difference between an e- current orbit (its ground state) and higher energy orbit (its excited state) -e- in an excited state can return to a lower energy orbit by emitting a photon equal in energy to the energy difference between the energy levels. An e- can return to its ground state either in a single transition or in multiple transitions Ex, photon of light hits an e-. It gets excited and jumps to a higher energy level (E1, E2, E3, etc). Eventually, the excited state e- comes back down to its ground state via the release of energy (photon) *Note, excited state = not gaining or losing e-, the valence e- present are absorbing energy (via photons) and being moved to a diff subshell/shell. (atomic nucleus)

Electron affinity:

-electron affinity is the amount of energy released when something gains an e- (how easily it can gain an e-). Efinal-Einitial -some elements release energy upon the addition of an e- (exothermic, negative values) -some elements (w a closed shell or subshell) tend to require energy upon addition of an e- (endothermic, positive values) PERIODIC TREND= *electron affinity decreases as you go down a group bc of increasing radii; less negative, less exothermic *electron affinity increases as you go across a row; more negative, more exothermic **highest e- affinity = halogens **lowest e- affinity = noble gases **local minima occurs for filled subshells and half-filled p subshells (very little energy is released) -as Felectrostatic and/or effective nuclear charge increases, the addition of electrons give off more energy (more exothermic) (periodic table; group and row)

Electronegativity:

-electronegativity is how much something hoards electrons in a covalent bond F > O > N > Cl > Br > I > S > C ~ H PERIODIC TRENDS= -F is the most electronegative element -things around F are highly electronegative, O, N, Cl, Br -halogens are electronegative, especially toward the top of the group -noble gases can be very electronegative if they participate in bond formation (Kr and Xe) -nonmetals are more electronegative than metals -as Felectrostatic and/or effective nuclear charge increase, the ability to attract electrons increases, Felectrostatic ∝ EN -covalent bond is a sharing of e- between elements. The more electronegative element in a covalent bond gets a larger share of the electrons and has a partial negative charge. The less electronegative (more electropositive) element in a covalent bond gets a smaller share of the electrons and has a partial positive charge -if the electronegativity diff is too great, an ionic bond occurs (instead of a covalent bond). Ionic bonds result from complete transfer of electrons from the electropositive element to the electronegative element (periodic table; group and row)

Element vs atom vs molecule vs compound:

-element - a basic substance that can't be simplified (hydrogen, oxygen, gold, etc) -atom - the smallest amount of an element -molecule - two or more atoms that are chemically joined together (H2, O2, H2O, C6H12O6, etc) -compound - a substance that contains more than one element (H2O, C6H12O6, etc)

Simple harmonic motion of a spring:

-equilibrium position= when the spring is neither stretched or compressed, it is at its equilibrium position. Fnet=0, the spring is at its natural length. The position is denoted as x=0 -maximum displacement, max x= amplitude. Can be +A (max extension) or -A (max compression) -restoring force= the spring exerts a restoring force on the block that's proportional to its displacement, F ∝ -d. The restoring force exerted by the spring maintains the oscillations. The restoring force, is given by Hooke's Law: F=-kx, where F is the restoring force, k is the spring constant (stiffer springs have a higher k value), and x is the displacement (the amplitude, A, is the maximum x value) -since the force is changing as the block moves, acceleration is not constant -the spring stores energy, called elastic potential energy. This is given by: PE = 1/2kx² *remember that force in the same direction as displacement is positive work. While force in the opposite direction as displacement is negative work. W by spring= -ΔPE W against spring= +ΔPE -since the block attached to the spring is moving, it has kinetic energy associated with it. This is given by: KE = 1/2mv² *we can look at the motion of the block from the point of view of the back-and-forth transfer between elastic PE and KE the dynamics of the oscillations can be summarized by: 1)at x = -A, Magnitude of restoring force= max; Magnitude of acceleration= max; Elastic PE of spring= max; KE of block= 0; Speed (v) of block= 0 2)at x = 0, Magnitude of restoring force= 0; Magnitude of acceleration= 0; Elastic PE of spring= 0; KE of block= max; Speed, v, of block= max 3)at x = +A, Magnitude of restoring force= max; Magnitude of acceleration= max; Elastic PE of spring= max; KE of block= 0; Speed, v, of block= 0 -bc we're ignoring any frictional forces during the oscillations of the block, total mechanical energy will be conserved. At any point, PE+KE = maximum PE = maximum KE = constant *constant= PEmax= 1/2kA² *constant= KEmax= 1/2mv², at x=0 -max velocity occurs when the block is at x=0, the equilibrium point. At this point, all PE → KE. We say that 1/2kA² = 1/2mv², and vmax= A√k/m -additionally, the frequency and period only depend on the spring constant, k, and the mass of the block, m. Frequency and period DO NOT depend on the amplitude. This is shown by: f=1/(2𝝿) √k/m T=2𝞹 √m/k OR ω=√k/m, where ω is the angular frequency (ω=2𝞹f) *if a mass on a spring is pulled back 1cm or pulled back 10cm, the time it takes to complete one cycle is exactly the same. Frequency and period do not depend on amplitude. *frequency and period only depend on k and m. The spring vibrates faster if its stiffer (larger k) and if the mass attached to it is smaller (smaller m). (periodic motion)

Properties of density:

-external pressure is directly proportional to density, P ∝ 𝝆 For ex, if you have a sponge (normally low density) and you squeeze it together (apply pressure), its density increases -intermolecular forces are directly proportional to density, IMF ∝ 𝝆 For ex, more intermolecular forces between molecules, (possibly something in the solid state), = higher density -external temp is indirectly proportional to density, 𝝆 ∝ 1/T Ex, if you have liquid water and you increase the temp, it will turn to vapor (gas phase), therefore, the density is decreasing density ∝ IMF ∝ pressure ∝ 1/T *remember, density is a measure of how condensed a substance is, mass/volume. Expressed by: 𝝆 = m/V, with units of kg/m³ or g/cm³ *the density of liquid water is, 𝝆 = 1g/mL = 1g/cm³ = 1kg/L = 1000 kg/m³ (for conversion, 1kg = 1000g, 1L = 1000mL, 1³m³ = 100³cm³) (gas phase)

If 5amps of current flowed in the NaCl electrolytic cell for 1930 seconds, how much sodium metal and chloride gas would be produced?

-first, we know that It=nF, so 5(1930)/n(96,500) → n= 0.1mol e- -second, use the stoichiometry half-reactions to finish the calculation: First, Na+ + e- → Na 1 mol of e- gives one mol of Na. Therefore, 0.1mol of e- gives 0.1mol of Na. *the molar mass of Na is 23g/mol. So, (0.1mol)(23g/mol) → 2.3g of sodium metal deposited on the cathode Second, 2Cl- → Cl2(g) + 2e- 1 mol of e- lost gives 1/2 mol of Cl2(g). Cl2 and the 2e- are in a 1:2 ratio. So, 0.1mol of e- gives 0.05mol of Cl2(g) *the molar mass of Cl2 is 70g/mol. And, (0.05mol)(70g/mol) → 3.6g of chlorine gas was liberated near the anode. (electrochemistry)

What is the electron configuration for Fe²⁺

-for a cation or anion, first write the configuration of the neutral atom and THEN add or remove electrons appropriately -if you have an ion, e- are first removed from valence orbitals -even though 3d is higher in energy than 4s, the valence 4s e- are removed before the non-valence 3d e- *e- configuration for Fe = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁶ -or can be written as [Ar] 4s² 3d⁶ -it can also be written as [Ar] 3d⁶ 4s² *e-configuration for Fe²⁺ = [Ar] 3d⁶ (electronic structure)

Alkaline earth metals:

-group 2, s-block -2 valence e-, relatively low in ionization energy, quite reactive -wants to lose both e- to achieve empty valence shell -more reactive as you go down bc of increasing radii -reacts w oxygen to form oxides -reacts w water to form hydroxides and releases hydrogen -reacts w acids to form salts and releases hydrogen -most commonly found in the +2 oxidation state (the periodic table; electronic structure)

Halogens:

-group 7, p-block -7 valence e-, high e- affinity, very reactive *e- affinity has a large negative value (exothermic rxn, tons of energy released when an e- is added). Very high ionization energy (does not want to lose an e-) -wants to gain one e- to achieve full valence shell *halogens tend to gain a single electron, either forming diatomic molecules or becoming reduced non-metal anions -more reactive as you go up bc of decreasing radii -reacts w alkali metals and alkaline earth metals to form salts -most commonly found in -1 oxidation state (the periodic table; electronic structure)

Going from a gas → liquid → solid:

-heat is given off, -ΔH, this is an exothermic process, energy is released -can occur by decreasing the temp -internal KE decreases -entropy decreases, -ΔS, less disorder -gas → liquid = condensation *the amount of heat needed to do this= -heat of vaporization, -ΔHvap -liquid → solid = crystallization/freezing *the amount of heat needed to do this= -heat of fusion, -ΔHfus -Deposition= going straight from gas → solid

Principle quantum number:

-in general, there are 4 quantum numbers which describe the electronic structure of the quantum model. These include n, l (angular momentum), m, etc. **Only need to know n -the principal quantum number, n, defines what shell the e- is in. It also describes the radial distance of an electron's orbit from the nucleus -n values range from 1, 2, 3, etc -high n shells are higher in energy (if subshells are the same). Another way to say this, electron energies are quantized *ex, 3s is higher in energy than 2s -the distance between orbits decreases w distance from the nucleus -there are n squared orbitals per shell *for ex, n=1 shell, 1^2 =1, thus there is only 1 orbital orientation *In the n=3 shell, 3^2= 9, thus there is 9 orbital orientations (in n=3 shell, you have subshells s, p, d. Subshell s = 1 orbital. Subshell p = 3 orbitals. Subshell d = 5 orbitals) -there are 2 electrons per orbital -thus, there are (2n)^2 electrons per shell *ex, n=1 shell has [(2)(1)]² → 4 total electrons in the first shell (atomic nucleus)

Phase changes that release heat:

-includes phase changes that bring molecules together -heat release = exothermic -includes: condensation, freezing/crystallization, deposition

Phase changes that absorb heat:

-includes phase changes that spread molecules out -heat absorbed = endothermic -includes: melting/fusion, vaporization, sublimation

Describe fluid flow at different velocities:

-low velocity → laminar flow, the individual streamlines don't cross; smooth flow -high velocity → turbulent flow, forms eddies; whirlpools; vortexes (fluids)

Mass vs Weight:

-mass= a measurement of the amount of matter something contains. Mass is given in kg. It is a magnitude, no direction (scalar). -weight= a measurement of the pull of gravity on an object. If on earth's surface, then weight=(mass)(Fg). Weight is given in newtons, it is a force. It has a magnitude and a direction, (vector). Ex, a 100kg man on earth vs being on the moon *for mass, at either place, he is 100kg *for weight, on earth's surface, he is (100kg)(10)= 1000N. On the moon his weight would be diff (Force)

Molecular mass vs molecular weight:

-molecular mass is measured in amu -molecular weight is measured in g/mol *numerically, the two are approximately equal to each other The weights given on the periodic table = 1 mole of something Thus, 1amu = 1g/mol Ex, 1 atom of Na = 23amu and 1mole of Na = 23g -one mole of anything contains 6x10²³ atoms. This is called Avogadro's number. #moles = mass in grams of sample/MW Ex, how many moles of hydrazine, N2H4, are in a sample w a mass of 96g? n=96g/32 → 3 moles

Half reactions:

-oxidation half reaction describes the species that loses e- (increase in charge). For ex, Cu → Cu²⁺ + 2e- -reduction half reaction describes the species that gains e- (decrease in charge. For ex, 2Ag⁺ + 2e- → 2Ag *note: Ag is silver! (electrochemistry)

Charge and mass of a proton vs neutron vs electron:

-proton (p+): charge of +1 elementary unit, mass of 1amu -neutron (n₀): charge of 0 elementary units, mass of 1amu -electron (e-): charge of -1 elementary unit, mass of 0amu (atomic nucleus)

Compare real weightlessness vs apparent weightlessness:

-real weightlessness= when there is no net gravitational force acting on you. Either you are so far out in space that there's no objects around you for light-years away, or you are between two objects w equal gravitational forces that cancel each other out. -apparent weightlessness= this is what "weightlessness" really means when we see astronauts orbiting in space. The astronauts are falling toward the earth due to gravitational forces (weight), but they are falling at the same rate as their shuttle, so it appears that they are "weightless" inside the shuttle. (Equilibrium)

Oxygen group:

-refers to the group/column that contains oxygen -oxygen and sulfur are chemically similar, have the same chemical reactivity -Se= non-metal, Te= metalloid, Po= metal or metalloid (the periodic table; electronic structure)

What are the three fundamental properties of sound?

-reflection (bouncing off objects) -refraction (bending of a wave when it meets a boundary, like going from air to water) -diffraction (going around objects) (sound)

Representative elements:

-representative elements include the s-block and p-block of the periodic table -no free flowing/loosely bound outer d electrons -valence shell fills from left to right (1e- to 8e-) -standard nomenclature from left to right is: IA, IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA (the periodic table; electronic structure)

Rutherford model vs Bohr model vs Quantum model:

-rutherford model= e-'s assume arbitrary orbitals -bohr model= e-'s assume quantized orbitals. Used w one e- species, like H, He+, Li²⁺, etc -quantum model= e-'s exist in a "spherical probability cloud" around the nucleus. Used w more than one e- species. Takes shielding of electrons into account (atomic nucleus)

Mass spectroscopy:

-sample is put inside a mass spectrometer -molecules in your sample are bombarded with a high energy beam of electrons, which causes them to become ionized. These ions have a characteristic mass to charge ratio (m/e or m/z). The mass to charge ratio is the ratio of particle mass over ionization. Most molecules are ionized once with a charge of +1, (have lost one electron), so the m/z ratio can simply be viewed as molecular mass -once ionized, compounds enter a region of the spectrometer where they are acted on by a magnetic field. This field causes the flight path of the charged species to alter, which resolves (separates) the different m/z ions so they can be individually detected and plotted on a spectrum. If your molecule was not ionized, it will not be detected in the mass spectra. -the mass spectra plots the 'relative abundance vs m/z ratio' On the spectrum: *base peak= the tallest peak, this is your most abundant species *parent peak or molecular ion peak= the peak that depicts the ion of the molecule without fragmentation. It has the highest m/z ratio. *peaks clustered really close to the base peak or parent peak (molecular ion peak) represent molecules that contain one or more abundant isotopes (for ex, hydrogen-1 vs hydrogen-2, carbon-12 vs carbon-13, etc) *peaks with a lower m/z value represent the masses of molecular fragments. The high energy beam of electrons used to ionize molecules in the mass spec can cause the molecule to break into smaller parts *The faster (higher energy) the bombarding electron, the more fragmentation. *The more fragmentation, the smaller the molecular ion peak. Note: particular atoms in a molecule may give characteristic peaks in their mass spectra. For ex, bromine naturally occurs in two isotopes (bromine-79 and bromine-81) of nearly identical natural abundance. Any mass spectra with a brominated compound will have two major peaks. Chlorine also occurs in two major isotopes (chlorine-35 and chlorine-37). Mass spectra for chlorinated molecules will have two main peaks. *purpose: allows you to determine the mass of compounds in a sample. (molecular structure and absorption spectra)

A solute in water can be a _________.

-strong electrolyte (complete dissociate), ionic compounds, metal + nonmetal -weak electrolyte (partially dissociates), weak acid or weak base -nonelectrolyte (no dissociation), molecular compound, nonmetal + nonmetal **nonelectrolytes can be polar or nonpolar. **polar nonelectrolytes will dissolve in water (soluble; will become surrounded by water molecules) but will not dissociate (no ions) **nonpolar nonelectrolytes will not dissolve in water (hydrophobic; not soluble; do not want to become surrounded by water). Additionally, they do not dissociate (no ions) (gas phase)

Phase transition diagram/heating curve:

-the amount of heat during a phase change is given by: q = nΔH *where n is the number of moles. *if ΔH and q are positive, heat is absorbed. If ΔH and q are negative, heat is released -the amount of heat not during a phase change is given by: q=mcΔT *where m is the mass of the sample, c is the specific heat of the substance -phase transition diagram/heating curve: as heat is added to the solid, its temp increases until it reaches its mp. At that point, absorbed heat is used to change the phase to liquid, not to increase the temp. Once the sample has been completely melted, additional heat again causes its temp to rise, until the bp is reached. At that point, absorbed heat is used to change the phase to gas, not to increase the temp. Once the sample has been completely vaporized, additional heat causes its temp to rise. -we can summarize this using a phase transition diagram, which plots the temp of the sample vs the amount of heat absorbed, q (gas phase)

The energy of a photon is related to its _________.

-the energy of a photon is related to its wavelength and frequency E=hf=hc/ƛ, E is energy, h is Plank's constant (6.63x10 ⁻³⁴ Jᐧs), f is frequency, c is speed of light (3x10⁸ m/s), and ƛ is wavelength. In summary, *Energy α Frequency, energy and frequency are directly proportional to each other (if you increase energy, you increase frequency) *Energy α 1/wavelength, energy and wavelength are inversely proportional (large wavelength means a small energy) *Frequency α 1/wavelength, frequency and wavelength are inversely proportional (large wavelength means a slow frequency) (atomic nucleus)

Effective nuclear charge:

-the nuclear charge experienced by a valence e- is called the effective nuclear charge. Effective nuclear charge = atomic number - shielding electrons OR, Zeff = Z - core e-, remember Z is just the atomic number, (# of p+) *Zeff is USUALLY equal to your number of valence e- -core e- shield the valence e- from the full nuclear charge -valence e- experience an electrostatic attraction (Felectrostatic) due to the nucleus; e- are attracted to p+ in the nucleus. This can be given by Coulomb's law, Felectrostatic=k(q₁q₂/r²), k is coulomb's constant, q₁ and q₂ are the charges, and r² is the distance between charges (how far e- is from p+) To better look at Zeff, we devise a new formula: Felectrostatic = Zeff + C/r², Zeff is the number of valence e-, C is charge, and r is radius (shell, n value) *if Felectrostatic is high, the valence e- are getting pulled into the nucleus tightly Felectrostatic ∝ charge of atom Felectrostatic ∝ effective nuclear charge Felectrostatic ∝ 1/r^2 -the higher the effective nuclear charge (Zeff) for an e-, the more stable it is (higher ionization energy, not easily knocked off). PERIODIC TRENDS= 1)moving down a group: -Zeff remains constant, same number of valence e-'s -Felectrostatic decreases, bc your shell number, n, is increasing 2)moving across a row: -Zeff increases, valence e-'s are increasing -Felectrostatic increases, your shell number, n, remains constant. But Zeff is increasing 3)moving from positive to negative in charge= -Zeff remains constant, your atomic number (number of p+'s) and core e-'s remains constant -Felectrostatic decreases as an element gets more negative. This is bc the charge, C, becomes negative (periodic table; group and row)

Theoretical yields:

-the theoretical yield is how much of the product will be made based on stoichiometry -when calculating your theoretical yield, first find out what your limiting reactant. Then use your limiting reactant as a stoichiometric basis to calculate how much product you will get -in real life, the experimental yield is always less than the theoretical yield bc of loss during steps of the reaction. *weird exception, the experimental yield could be higher than your theoretical yield if you accidently dumped in more reactant/added too much, etc. -from the theoretical yield and experimental yield, you can also calculate the percent yield. Percent yield = experimental yield / theoretical yield x 100 Ex, what is the theoretical yield for 3Xred? 3Xox + Ared → 3Xred + Aox Given: you use 60g of Xox and 63g of Ared Given: the molecular weight of Xox is 2amu, Ared is 7amu, and Xred is 10amu To solve: 1)LIMITING REAGENT: to solve, the first thing to do is convert everything to moles 1amu=1g//mol Xox: 2amu=60g//mol → 60g/20amu → 30mol Ared: 7amu=63g//mol → 63g/7amu → 9mol *now, use stoichiometry. Divide the moles by the stoichiometric coefficient of the species: 30mol/3 → 10 for Xox 9mol/1 → 9 for Ared *Now, compare the values. 9 is the smallest. So, Ared is the limiting reactant. 2)THEORETICAL YIELD: first, take the amount in moles of the limiting reagent and do the stoichiometry to see how many moles of 3Xred this will yield (9mol Ared)(3molXred per 1mol of Ared) = 27mol of Xred *lastly, convert moles to grams: (27mol)(10g//mol) → 270g of Xred, this is your theoretical yield for 3Xred. **Say you did the actual experiment and you managed to obtain 243g of Xred. Thus, the experimental yield would be 243g. To get percent yield, you would do: 243/270 x 100 → 90%

Beta decay:

-there are three types of beta decay, beta-, beta+, and electron capture. -each type of beta decay involves the conversion of a neutron into a proton, or a proton into a neutron. -energy/harm: beta particles are more dangerous than alpha particles since they are less massive (have more energy and can penetrate things better). However, they can be stopped by plastic/glass/etc. 1) 𝛃- decay= an unstable nucleus contains too many n. So, a n is converted to a p+ and an e- (the e- is called a 𝛃- particle). The 𝛃- particle is then ejected. n → p+ + e- *decreases the number of n, increases the number of p+ -increases the parent's atomic number by 1, (one more p+) -no change in the parent's mass number, (same amount of n + p+) *this is the most common type of beta decay. If the mcat mentions just "beta-decay," or "beta-emission" it is talking about 𝛃- decay. 2) 𝛃+ decay= also called positron emission. An unstable nucleus contains too few n. So, a p+ is converted to a n and a positron, the positron is then ejected. The positron is the e- antiparticle; its identical to the e- except its charge is positive. p+ → n + positron *increases the number of n, decreases the number of p+ -decreases the parent's atomic number by 1 (one less p+) -no change in the parent's mass number (same number of n + p+) 3) electron capture= an unstable nucleus contains too few n. So, it captures an e- from the closest shell, (the n=1 shell), and uses it to convert a p+ into a n. p+ → n *increases the number of n, decreases the number of p+ -decreases the parent's atomic number by 1 (one less p+) -no change in the parent's mass number, (same amount of n + p+) (atomic nucleus)

Redox titrations:

-titration of a redox active species with either a strong oxidant (oxidizing agent) or a strong reductant (reducing agent). Redox titrations are used to determine the concentration of an unknown solution (analyte) that contains an oxidizing or reducing agent. -The titrant is the standardized solution; the analyte is the analyzed substance. -Most redox titrations involve the use of a redox indicator (changes color to determine when the endpoint is reached). However, not all titrations require an external indicator. -types of redox titrations= iodimetric and iodometric titrations Ex of a redox titration: MnO₄⁻ + 5Fe²⁺ + 8H+ → Mn²⁺ + 5Fe³⁺ + 4H2O -you have a flask containing an unknown concentration of Fe²⁺ ions. You want to know the concentration of Fe²⁺ in this solution. It is a clear (no color), acidic solution (maybe contains some sulfuric acid, H₂SO₄), and you have a total of 10mL of it. -you decide to use potassium permanganate (KMnO₄), at a 0.02M concentration to titrate this solution. Potassium permanganate is purple in color. -you slowly add the titrant, drip by drip. It will enter the flask and become K+ and MnO₄⁻. This provides a source of permanganate anions. This causes a redox reaction. *Mn has an oxidation state changing from +7 to +2, oxidation state is decreasing. Mn is becoming reduced (gaining electrons) *Fe has an oxidation state changing from +2 to +3, oxidation is increasing. Fe is becoming oxidized (losing electrons) -As you add your titrant to the flask (here, potassium permanganate), the titrant changes from purple to clear. This is bc MnO₄⁻ undergoes a redox rxn with Fe²⁺ -Suddenly, while slowly adding your titrant, the flask changes to a persistent light purple color. This indicates the endpoint of the titration. *color change occurs bc there is too much MnO₄⁻. Not all of it can react with Fe²⁺. So, instead of getting your colorless products, Mn²⁺ + 5Fe³⁺, you end up with excess, unreactive permanganate ions in your solution. *you have reacted all the Fe²⁺ which was originally present -next, you look at how much titrant you used. For ex, here we used 20mL of potassium permanganate (KMnO₄). *now, determine how many moles of titrant were used. M = mol/L → 0.02 = mol/0.02L → 0.0004mol MnO₄ were needed to react all the Fe²⁺ which was originally present -determine how many moles of Fe²⁺ were originally present. To do this, use the balanced redox equation to look at mole fractions, (ratio of titrant compared to analyte) *mole fraction of MnO₄⁻//Fe²⁺, this is a 1:5 ratio *we know that 0.0004mol MnO₄ were needed to react all the Fe²⁺ which was originally present. Since MnO₄⁻ and Fe²⁺ are in a 1:5 ratio (0.0004)(5) → 0.002 mol of Fe²⁺ originally present in the 10mL flask. **Finally, to get total concentration of Fe²⁺ originally present, M=mol/L [Fe²⁺] = 0.002mol/0.01L → 0.2M. https://www.youtube.com/watch?v=EQJf8Gb8pg4

Reduction potentials vs oxidation potentials:

-to determine whether the redox rxn of an electrochemical cell is spontaneous and can produce an electric current, we need to figure out the cell voltage. -reduction potential is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. -it is measured in volts (V) -the standard reduction potential is written at E° -each species has its own intrinsic reduction potential; the more positive the potential, the greater the species' affinity for electrons and tendency to be reduced. -each half-reaction has a potential (E), which is the cell voltage it would have if the other electrode were the standard reference electrode. By definition, the standard reference electrode is the site of the redox rxn 2H+ +2e- → H2, which is assigned a potential of 0V. -by adding the half-reaction potential for a given pair of electrodes, you get the cell's overall voltage -tables of half-reaction potentials are given for reductions only. To get the oxidation half-reaction potential, you simply just reverse the sign of the given reduction potential *in summary: -reduction potential: potential of the reduction half reaction -oxidation potential: potential of the oxidation half reaction. You must reverse the sign of the reduction potential -cell potential = reduction potential + oxidation potential *the cell potential for all galvanic/voltaic cells is positive bc the cell generates potential. Since the cell voltage is positive, the reaction is spontaneous *the cell potential for all electrolytic cells is negative bc the cell requires potential input. Since the cell voltage is negative, the reaction is nonspontaneous **we can additionally see the spontaneity for a redox rxn by using the equation: ΔG° = -nFE°, n=moles, F=faraday. The redox rxn in a cell will be spontaneous if the cell voltage is positive (electrochemistry)

Spontaneous fission:

-type of radioactive decay in which certain unstable nuclei of heavier elements split into two nearly equal fragments (nuclei of lighter elements) and liberate a large amount of energy. Ex, uranium can fission to yield strontium and krypton. U→ Sr + Kr *fission = an atomic nuclei is separated. *fusion = atomic nuclei joined together. (atomic nucleus)

Iodimetric titration:

-type of redox titration where we determine the concentration of a reducing agent (your analyte) by titrating w a standard iodine solution. The reducing agent (your analyte) reacts w iodine (I2) to produce iodide (I-). Ared + I₂ → Aox + 2I- -endpoint occurs when solution goes from color (brown or blue) to clear. -you have a flask containing an unknown concentration of a reducing agent. You want to know the concentration of this reducing agent. Your titrant is a standard iodine solution (you know the concentration of iodine in your titrant solution, and you will add a specific volume of titrant to your flask (slowly, drip by drip)). -as you add this titrant, (iodine (I2)), will react with the reducing agent. Electrons will be transferred to I2, forming: Ared + I₂ → Aox + 2I- *the reducing agent becomes oxidized (giving iodine electrons) -iodide (I-) is yellow/brown in color -iodine (I₂) is clear in color -eventually you will reach the endpoint, when solution turns clear *clear color change occurs bc there is too much iodine (I₂). Not all of it can react with the reducing agent (the analyte). So, instead of getting your colored product (I-), you end up with excess, unreactive iodide in your solution. -ISSUE: there is NOT a sharp/clear endpoint. Endpoint hard to see bc solution goes from brown, yellow, to clear. Bc of this, iodine is used in redox rxns in the presence of starch. I2-starch is dark blue, while I- is colorless. This gives a definite/clear endpoint. *using a standard in iodimetric titrations: 1)Sox + 2I- → Sred + I2 (taking e- from iodine) 2)Ared + I₂ → Aox + 2I- (giving e- to iodine) Note: Your titrant is a standard iodine solution (you know the concentration of iodine in your titrant solution, and you will add a specific volume of titrant to your flask. Here, step 1 just makes sure that the I₂ produced is of accurate amount/concentration by the use of a standard.

Iodometric titration:

-type of redox titration where you determine the concentration of an oxidizing agent (your analyte) in a given sample solution. 1)Aox + 2I- → Ared + I2 2)Tred + I₂ → Tox + 2I- -endpoint occurs when solution goes from color (brown or blue) to clear. *starch + I₂ → dark blue *starch + I- → nothing/clear Ex: FIRST) you want to determine the concentration of an oxidizing agent, HOCl, in a given sample solution. To do this, you first add a ton of I-, (iodide), to the solution (iodide will be in the form of HI, NaI, etc. Iodide is not stable by itself). HOCl + 2HI → I₂ + HCl +H2O *another way to write it, Aox + 2I- → Ared + I₂ *iodide gets oxidized to iodine. The solution turns dark brown in color. *Now in solution, you no longer have HOCl. But you have a certain concentration of I₂, which corresponds to how much HOCl (an oxidizing agent) you originally had SECOND) you titrate with a standard solution thiosulfate (S₂O₃²⁻). This is a reducing agent. Note: standard solution means you know the concentration of thiosulfate in your titrant, and you know how much titrant you are adding. *slowly, I₂ gets converted to I-. Iodine becomes reduced, solution will turn clear once endpoint is reached. Tred + I₂ → Tox + 2I- *clear color change occurs bc all the I₂ has been converted to I- by thiosulfate. *you must use a standard solution of thiosulfate (known concentration and amount) bc you need to know how much I₂ you made in the previous step, which will allow you to quantify how much HOCl there was in your original sample.

Alpha decay:

-when a large nucleus wants to become more stable, it loses an alpha-particle, consisting of two p+ and two n -this is equivalent to a helium-4 nucleus, so an alpha particle can also be denoted by this -alpha decay reduces the parent's atomic number by 2 -alpha decay reduces the parent's mass number by 4 -energy/harm: alpha particles are emitted w low speed from the parent nucleus. The particles do not travel far, and can be stopped by the outer layers of human skin Ex, polonium-210 undergoes alpha decay to form the stable nucleus lead-206 (atomic nucleus)

Oxidizing agents:

-will oxidize something else, and in turn become reduced (takes e-, an e- acceptor) -an atom that is reduced in a reaction gains e- from another atom. We call the reduced atom a oxidizing agent/oxidant, bc by gaining e-, it oxidizes another atom which loses the e- *In one sense, an oxidizing agent is a chemical species that undergoes a redox reaction and removes one or more e- from another atom. In another sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, to a substrate -common oxidizing agents = STUFF W A LOT OF OXYGENS (something w a high affinity for electrons, like O₂, O₃, F₂, Cl₂, other halogens); peroxides; something w unusually high oxidation states (like Mn⁷⁺ in permanganate, MnO₄⁻ and Cr⁶⁺ in chromate) *most common oxidizing agents: -oxygen, O₂ -ozone, O₃ -fluorine, F₂ -chlorine, Cl₂ -peroxides, (a peroxide is a compound w an oxygen-oxygen single bond. The most simplest peroxide is hydrogen peroxide, H₂O₂). Note, peroxidase is an enzyme which catalyzes peroxide reactions. -permanganates, MnO₄⁻ -chromates, CrO₄⁻² -dichromates, Cr₂O₇⁻² (chromate salts contain the chromate anion, CrO₄⁻². Dichromate salts contain the dichromate anion, Cr₂O₇⁻²) -lewis acids/electrophiles (accepts an e- pair) (electrochemistry)

Conservative forces:

-work done by conservative forces are path independent. Only care about point A → point B. Do not care about path taken. For ex, the work done by gravity, Wg, is the same whether you pick an object straight up or you slide the object up an inclined ramp -if a force doesn't dissipate heat, sound, or light, then it is a conservative force -if a conservative force is the only force doing work, mechanical energy is conserved -conservative forces have potential energies associated w them. For ex: *the force from a spring can be stored as spring potential energy *the gravitational force can be stored as gravitational potential energy -conservative forces include: gravity, electrostatic/electromagnetic force, spring force -non-conservative forces include: friction, drag, and human exertion. When friction acts on an object, the heat and sound released cannot be recovered (note, the frictional force converts KE to heat and sound energy). When you flex your arm, you lose heat that cannot be recovered (you cannot reabsorb the heat you lost). If a non-conservative force is doing work, mechanical energy is not conserved. This can be expressed by: KEi + PEi + Wnon-conservative = KEf + PEf or Wnon-conservative = ΔE (energy of point object systems)

The four fundamental forces/universal forces of nature:

1) The strong force: also called the nuclear force. It is the strongest of all the four forces, but it only acts at subatomic distances. It binds nucleons together. 2) electromagnetic force: about one order of magnitude weaker than the strong force, but it can act at observable distances. Includes electric and magnetic effects, such as repulsion between like electrical charges or the interaction of bar magnets. It can be attractive or repulsive. Binds atoms together; Allows magnets to stick to your fridge; It is responsible for the fact that you are not falling through your chair right now. 3) weak force: roughly 10 orders of magnitude weaker than the strong force. It is the the mechanism of interaction between subatomic particles. Responsible for radioactive decay 4) gravity: roughly 50 orders of magnitude weaker than the strong force. Responsible for weight (not mass!). Also, responsible for planet orbits. Gravitational force is weak, but very long ranged. Always attractive. (Force)

Separating blood plasma from the solid bodies in blood (blood cells and platelets) by rapid sedimentation requires use of a centrifuge to produce the necessary accelerations on the order of 5000g. In one approach, the blood is placed in a bag inside a rigid container and mounted to the end of a horizontal rotor (so that it extends out beyond the rotor), which then spins up to several thousands of revolutions per min. Suppose the rotor has a radius of 30cm and rotates at a max rate of 5000rpm, and that the bag is 10cm long. Note that translational velocity, v=rω, where ω is in radians/second. A) What will be the centripetal acceleration at the middle of the bag? B) will the centripetal acceleration increase or decrease for the blood further from the axis of rotation?

1) first, convert rpm to rad/s. There are 2𝝅 rad per 1 revolution. So: (5000rev/1min) (2𝝅 rad/1rev) (1min/60sec) → 500 rad/s. -now, v=rω → v=(.3m + .05m)(500rad/s) → 175m/s is the tangential velocity -so, for the centripetal acceleration, ac=v²/r → ac= (175m/s)²/.35m, which is app 200²/.5, this makes the math easier! So, ac = 8x10⁴ m/s² *this is 8000g, so more than enough acceleration to achieve separation of blood. 2) As you get farther from the axis of rotation, the centripetal acceleration increases and the translational velocity increases (as you get farther from the center, you are moving faster). The angular velocity, ω, is constant. Note: ac α r (Force)

In regards to rotational motion, define: tangential velocity, angular velocity, centripetal acceleration, force centripetal, angular acceleration, tangential acceleration, angular momentum

1) tangential velocity: *velocity tangent to the circle of rotation *In UCM, the tangential velocity is constantly changing bc of a change in direction *expressed by: v=rω, where ω is the angular velocity 2) angular velocity: *in UCM, the angular velocity is constant bc there is a constant change in radians/second *if speeding up or slowing down, there will be a change in angular velocity *expressed by: ω=rad/sec=2π(frequency)=2π/period, where frequency is measured in Hz and is given by f=rev/sec=1/period **note: two points on an object undergoing rotational motion; both points will have the same angular velocity, but they will have diff tangential velocities. The point that is farther from the axis of rotation will have a larger linear or tangential velocity 3) acceleration centripetal or radial acceleration: *the acceleration directed towards the center of the circle. In UCM, bc velocity tangential is continually changing, there is a centripetal acceleration. Points in the same direction as force centripetal. Perpendicular to tangential velocity. Forces and acceleration that point perpendicular to velocity cannot change the speed; it only keeps the object moving in a circle *expressed by: a=v²/r 4) force centripetal: *the force directed towards the center of the circle. Points in the same direction as acceleration centripetal. Forces and acceleration that point perpendicular to velocity cannot change the speed; it only keeps the object moving in a circle *expressed by: Fcentripetal=ma=mv²/r 5) angular acceleration: *used when talking about an object speeding up or slowing down moving in a circle *expressed by: α=∆ω/∆t *can also be looked at as similar to F=ma, so, torquenet=Iα, where I is inertia (how resistant something is to acceleration; depends on mass and distance from center of rotation), and α is angular acceleration 6) tangential acceleration: *acceleration tangent to the circle. Related to tangential velocity. If an object is speeding up or slowing down it will have a tangential acceleration *expressed by: a=rα Summary: there are three diff types of acceleration when talking about rotational motion. *With UCM, there is only a centripetal or radial acceleration (this keeps the object moving in a circle). The tangential acceleration and angular acceleration equal zero. *If an object begins to speed up or slow down (no longer UCM), then there is a centripetal or radial acceleration, a tangential acceleration, and an angular acceleration. 7) angular momentum: *used to talk about how much "oomph" something has when moving in a circle *similar to p=mv, L=Iω=rmv, where I is inertia and ω is angular velocity (rad/second), r is radius, m is mass, and v is velocity

Parallel plate capacitors have two main uses:

1) to create a uniform electric field: the electric field that's created between the plates of a charged parallel-plate capacitor is constant in both magnitude and direction throughout the region between the plates (this is different than an electric field from a source charge!). The electric field, E, always points from the positive plate toward the negative plate. The strength of E depends on the voltage between the plates, V, and the distance between the plates, d. This equation is called "Ed's formula," V=Ed, with units of volts per meter 2) to store electrical potential energy: during the charging process, an outside agent (the voltage source) must do work against the electric field that's created between the two plates of the capacitor. Once we begin the process of transferring electrons from one plate to the other, it becomes increasingly difficult to transfer more. After all, it takes effort to remove electrons from the plate that is left positively charged, and it takes effort to place them on the plate that is negatively charged. The fact that we have to "fight" against the system means we're storing potential energy. PEelectric stored in a capacitor is given by: PE=½ QV = ½ CV² = Q²/2C *to intuitively think about the formula for PE, we transferred a total amount of charge, Q, fighting against the voltage that prevailed at each stage. If the final voltage is V, then the average voltage between the charging process is ½ V. *the work done by the battery to charge the capacitor = PE *way to remember PE=½ QV = ½ CV² and which term has the V² unit= "if you use the formula with the C in it, then you can See (C) the v²" (Circuit Elements)

Weight on an elevator:

1) you weight more on an elevator accelerating up. Your weight is recorded by Fn that the scale exerts on you Fnet=ma → Fn - Fw = ma → Fn - mg = ma → Fn= mg + ma --> Fn=m(g+a) *when accelerating up, the acceleration is increasing (positive y direction). Thus, Fn is increased *an elevator accelerating up is the same thing as an elevator decelerating on its way down (acceleration is becoming less negative). Thus, Fn is increased 2) you weight less on an elevator accelerating down. Your weight is recorded by Fn that the scale exerts on you. When accelerating down, the acceleration is a negative value (negative y direction). Thus, Fn is decreased *an elevator accelerating down is the same as an elevator decelerating on its way up (acceleration is becoming less positive) (Force)

Balance the following redox reaction: MnO₄⁻ + 2I- → Mn²⁺ + I₂

1)Determine the oxidation number of each element. Reactants: Mn=+7, O=−2, I=−1 Products: Mn=+2, I=0 2)Write and balance each half reaction Oxidation (loss of electrons): 2I−(aq) → I₂(s) + 2e− Reduction (gain of electrons): MnO₄⁻ + 5e-→ Mn²⁺ *Balance oxygen by adding water (from the solution) into the half reactions. Oxidation: 2I−(aq) → I2(s) + 2e− Reduction: MnO₄⁻ + 5e −→ Mn²⁺ + 4H2O *Balance hydrogen by adding H+ ions from the acid into the half reactions. Oxidation: 2I−(aq)→I2(s)+2e− Reduction: MnO₄⁻ + 5e− + 8H+ → Mn²⁺ + 4H2O 3)Multiply each half reaction times an integer such that the electrons cancel when the equations are added. The oxidation reaction will be multiplied by five, and the reduction reaction will be multiplied by two. Oxidation times 5: 10I⁻(aq) → 5I₂(s) + 10e− Reduction times 2: 2MnO₄⁻- + 10e− + 16H+ → 2Mn²⁺ + 8H2O *Add the half reactions together. The electrons will cancel from both the reactants and products. 10I⁻ (aq) + 2MnO₄⁻ (aq) + 16H+ (aq) → 2Mn²⁺ (aq) + 5I₂(s) + 8H2O(l) https://www.varsitytutors.com/mcat_physical-help/half-reactions-and-balancing-equations

Ball 1 rolls w velocity v₁=5m/s toward ball 2, which is initially at rest. Ball 1 has a mass of m₁=1kg, and ball 2 has a mass of m₂=4kg. After the collision, ball 2 moves w a velocity of v'₂=2m/s. What's the velocity of ball 1 after the collision? Was this collision elastic or was it inelastic?

1)Using the conservation of momentum, we know ptotalbefore = ptotalafter m₁v₁ + m₂v₂ = m₁v'₁ + m₂v'₂ → m₁v₁ = m₁v'₁ +m₂v'₂ → (1kg)(5m/s)=(1kg)v'₁ + (4kg)(2m/s) → v'₁= -3m/s *the velocity of ball 1 after the collision is negative. This means it points to the left (since we arbitrarily called velocities to the right positive). We see here that when an object collides w a heavier object, the lighter object often bounces backwards 2) was this collision elastic or was it inelastic? To answer this, we need to know if total KE was conserved. KE before collision= 1/2m1v1^2 +1/2 m2v2^2 → ½(1kg)(5²) + 0 → 25/2 J KE after collision = 1/2m₁v'₁² +1/2 m₂v'₂² → ½(1kg)(3²) + ½(4kg)(2²) → 25/2 J *So, yes, KE was conserved. We can conclude the collision was elastic. (Equilibrium)

Rules for assigning oxidation states:

1)atoms in their elemental state have an oxidation number of zero. -For ex, H2, oxidation number = 0 2)the sum of the oxidation states of atoms in a neutral molecule must always be 0, and the sum of the oxidation states of the atoms in an ion must always equal the ion's charge 3)group 1 metals have a +1 oxidation state, and group 2 metals have a +2 oxidation state 4)fluorine has a -1 oxidation state 5)Hydrogen has an oxidation state of 0 when bonded to carbon. Hydrogen has an oxidation state of +1 when bonded to an atom more electronegative than C. Hydrogen has an oxidation state of -1 when bonded to an atom less electronegative than C. *hence, bonds from H to anything before C in FONClBrISCH will give H a +1 oxidation state, and bonds from H to anything not found in the list will give H a -1 oxidation state *the oxidation state of H will be -1 in metal hydrides, such as NaH, LiH, etc 6)oxygen has a -2 oxidation state. Except in peroxides (R-O-O-R), then oxygen's oxidation state will be -1. Or if oxygen is bound to fluorine (O-F), then oxygen has an oxidation number of +1. 7)the halogens have a -1 oxidation state. The atoms of the oxygen family have a -2 oxidation state (electrochemistry)

Conductivity theory:

1)conductivity is affected by electrolyte concentration: -no electrolyte, no ionization, no conductivity -Optimal concentration of electrolyte, greatest conductivity due to greatest mobility of ions. -Too much electrolyte, ions are too crowded, less ion mobility, less conductivity 2)Conductivity is affected by temperature: -In metals, conductivity decreases as temperature increases. -In semiconductors, conductivity increases as temperature increases. (note: semiconductor= a solid substance that has a conductivity between that of an insulator and that of most metals) -At extremely low temperatures (below a certain critical temperature typically a few degrees above absolute zero), some materials have superconductivity - virtually no resistance to current flow, a current will loop almost forever under such conditions. 3)Conductivity (σ) is the inverse of resistivity (ρ). 4)Place a capacitor inside a solution, the solution will conduct a current between the plates of the capacitor, thus you can measure the conductivity of a solution using a capacitor. (Circuit Elements)

Compare standard state conditions and STP:

1)standard state conditions= used for thermodynamic calculations -all gases are at 1atm pressure -temp = 25C or 298K -all aqueous reactants in the solution are present at 1M concentrations -substances are present in their standard states (standard states means how something naturally exists at room temp. For ex, mercury is liquid at room temp. That is its standard state) -the energy of formation of an element in its standard state is zero 2)STP= standard temperature and pressure. Used for calculations involving gases (ideal gases), when using the ideal gas law -all gases are at 1atm pressure -temp= 0C or 275K -1mol of gas occupies 22.4L (gas phase)

Two big rules for waves:

1)the speed of a wave is determined by the type of wave and the characteristics of the medium, not by the frequency. In other words, a wave traveling through a medium has a constant velocity. If frequency increases, wavelength decreases. If frequency decreases, wavelength increases. Either way, the velocity is constant. 2)when a wave passes into another medium, its speed changes, but its frequency does not. In other words, frequency is constant between media. If a wave is traveling from air into water, (a more dense medium), once the wave hits the water it will develop a larger wavelength and thus a larger velocity. The frequency, however, is the same. The rate in = rate out. Here, we see wavelength is proportional to wave speed *remember, wave speed is given by v=ƛf (periodic motion)

The molar volume of an ideal gas at 0 degrees Celsius and 1atm = ______.

22.4L/mol Note: *PV=nRT *R is constant, and at STP, pressure and temperature is also constant *V/n = RT/P *if you plug in STP values, you'll end up w V/n=22.4L/mol *all ideal gases at STP will occupy 22.4L per mol of gas molecules (gas phase)

Times tables, 9:

9x1 = 9 9x2 = 18 9x3 = 27 9x4 = 36 9x5 = 45 9x6 = 54 9x7 = 63 9x8 = 72 9x9 = 81 9x10 = 90 9x11 = 99 9x12 = 108 9x13 = 117 9x14 = 126 9x15 = 135 *And, 9²=81

Magnet:

A magnet is a material or object that produces a magnetic field. This magnetic field is responsible for the most notable property of a magnet: a force that attracts or repels other magnets. Not everything can be a magnet. Iron is the best magnet. *a magnet consists of a dipole, North and South poles. *there is a magnetic field around earth, which is why you can use a compass. The magnetic field inside the compass will align itself w the earth's magnetic field (Magnetism)

What is a fluid?

A material that flows/takes the shape of its container when at rest. Both liquids and gases are fluids. (fluids)

A block of mass 200g is oscillating on the end of a horizontal spring of spring constant 100N/m and natural length 12cm. A)When the spring is stretched to a length of 14cm, what is the acceleration of the block? B)if the block were replaced w a block of mass 800g, how would its maximum speed change?

A)So, the equilibrium point is x=.12m, you are stretching .02m, mass=.2kg, and k=100N/m Using Hooke's law, F=kx → F= (100N/m)(.02m) → F=2N Therefore, Newton's second law, F=ma → 2N/.2kg → 10m/s²=a B)using vmax= A√k/m, we see that if m increases by a factor of 4, (4m) then vmax will decrease by a factor of 2 (vmax/2) (periodic motion)

Consider two plastic spheres, 1m apart. A little sphere w a mass of 1kg and an electrical charge of +1nC, and a big sphere w a mass of 11kg and an electrical charge of +11𝜇C. A) find the electrical force and the gravitational force between these spheres. Which force is stronger? Note, G=6.7x10⁻¹¹ Nᐧm²/kg² B) if the big sphere is fixed in position, and the little sphere is free to move, describe the resulting motion of the little sphere if its released from rest.

A: *using coulomb's law, we find the electric force between the spheres to be, Felectrical = k |q1q2| /r² → (9x10⁹ Nᐧm²/C²) (11x10⁻⁶ C)(1x10⁻⁹ C) / (1m)² → 99x10⁻⁶/1 → 9.9x10⁻⁵ or 1x10⁻⁴ N *using Newton's law of gravitation, the gravitational force between them is, Fgravitational=G Mm/r² → (6.7x10⁻¹¹ Nᐧm²/kg²) (1kg)(11kg)/(1m)² → 74x10^-11 → 7.4x10^-10 N **As we see, the electrical force is much stronger than the gravitational force. So, even through the spheres experience an attraction due to gravity, it is many orders of magnitude weaker than their electrical repulsion and can therefore be ignored B: the net force on the little sphere is equal to the repulsion it feels from the big sphere. Therefore, the acceleration of the little sphere is: Felectrical=ma → 10⁻⁴ N=1kg(a) → a=10⁻⁴ m/s². This acceleration will be directed away from the big sphere. *bc the electrical force is inversely proportional to the square of the distance between the charges, as the little sphere moves away, the repulsive force it feels weakens, so its acceleration decreases. *nevertheless, bc the acceleration always points in the same direction (away from the big sphere), the speed of the little sphere is always increasing, although the rate of increase of speed gets smaller as the little sphere gets farther away (Electrostatics)

Non-ideal gases:

Also called "real gases." Real gas behavior deviates from ideal gases. Qualitative: 1)the Pideal > Preal. Bc the particles of a real gas DO experience intermolecular forces, their paths are deviated and thus the frequency of collisions on the container wall result in a lower pressure. 2)Videal > Vreal. Bc the particles of a real gas DO have physical size, they take up space in the container and thus the free space in the container is smaller. This can be expressed by: *ideal world is always > real world Quantitative: *to make predictions about about the deviations real gases show from ideal gas behavior, the ideal gas law must be altered. This is called the van der Waals equation, where: [P+a(n/V)²] [V-nb] = nRT, where a and b are van der Waals constants and are larger for gases that experience greater intermolecular forces (a) and have larger molecular weights, and therefore volumes (b) *the pressure term, P+a(n/V)², takes into account the attraction between real gas particles. The greater the value of "a" means there is more attraction, (more intermolecular interactions between gas molecules), thus pressure on the sides of the container is less *the volume term, V-nb, accounts for the volume occupied by the real gas particles. The greater the value of "b" means the size of the gas particles increases. Overall, this corresponds to less volume, (larger size of gas molecules means the molecules have less room to spread out; the free-space between particles is less; less volume) *the greater the value of "b" means gas molecules are larger in size. This will cause more repulsion between the molecules, which leads to a slightly greater pressure on container walls *the van der Waals equation is just an altered form of PV=nRT, accounting for the differences in P and V of a real gas vs an ideal gas Note: *when molecules are far apart (under conditions of low P, high T), they are ideal *when molecules are brought close together (higher P, lower T), they experience intermolecular attraction *when molecules are brought so close together that they clash into one another, they experience steric repulsion (gas phase)

What does an ammeter measure? Where should it be placed in a circuit? What is its ideal resistance? What does a voltmeter measure? Where should it be placed in a circuit? What is its ideal resistance?

An ammeter measures current and should be placed in series w the compose whose current it is measuring. Its ideal resistance is 0. A voltmeter measures voltage and should be placed in parallel w the component whose voltage it is measuring. Its ideal resistance is infinite

Why do people w bicep attachment points farther from their elbows tend to have greater elbow flexion strength, and thus an improved ability to perform a dumbbell curling exercise?

An attachment point that is farther from the elbow results in a greater torque produced by the bicep as it contracts *as radius from the pivot point increases, torque also increases (Equilibrium)

Electric dipole:

An electric dipole is a pair of equal, but opposite charges. The superposition of electric fields occurs when two or more source charges are present, whose electric fields overlap. An electric dipole is when the source charges whose electric fields overlap are equal and opposite in charge, +Q and -Q. *field lines come out of the positive end and go into the negative end of a dipole *notice that between the charges, where the field lines are dense, the field is strong. As we move away from the charges, the field lines get more spread out, indicating that the field gets weaker *a dipole in an electric field will want to align itself w the electric field, such that the positive end of the dipole is in the direction of the electric field (Electrostatics)

Bohr model of the ATOM:

An electron orbits the positively charged nucleus in the same way that the earth orbits the Sun; Electrons orbit at fixed distances from the nucleus. 1) Electrostatic attraction pulls the electron toward the nucleus. The Coulomb force provides the Fcentripetal for the e- 2) The electron orbits at high speed to prevent it from crashing into the nucleus. 3) The electron can orbit at different energy levels, denoted by the principal quantum number, n, where n=1, n=2, n=3, etc. 4) The electron energy levels are quantized and are related to their fixed-radius orbits (the higher the energy level, (larger n), the larger the radius from the nucleus). 5) the distance between orbits decreases w distance from the nucleus 6) atoms can change quantized energy states by absorbing or emitting a photon. The energy of the photon must correspond exactly to the energy difference between the two states: Ephoton= |ΔEatom|, energy is conserved 7) atoms can also change energy states thermally by interacting w other particles. Similar to when photons are absorbed, the changes in atomic energy are quantized, and excited atoms will tend to return to the ground state by emitting photons (this is why heated metal glows, for ex) Note: the bohr model works best with one electron species, like H, He+, Li²⁺, etc (atomic nucleus)

Galvanic vs Electrolytic cells:

BOTH: -oxidation at anode (M → M+ + e-) -reduction at cathode (M+ + e- → M) -electrons flow from anode to cathode -anions migrate to anode -cations migrate to cathode *electrolytes conduct electricity by the motion of ions. Without electrolytes, there won't be a circuit bc electricity won't be able to travel GALVANIC: -spontaneous, generates electrical power (ΔG < 0). On diagrams, instead of having a battery, you will see a resistor or a Voltmeter (voltmeters measure potential differences) -total E° of reaction is positive -galvanic/voltaic cells already have a positive cell potential. So, no input is required for electrolysis to occur -anode is negative -cathode is positive ELECTROLYTIC: -nonspontaneous, requires an external power source (ΔG > 0). On diagrams, this is represented by a battery in a circuit -total E° of reaction is negative -the potential/voltage input + the cell potential must be > 0 for the reaction to occur *note: the cell potential is negative, so a potential input which is greater than the magnitude of the cell potential must be present for electrolysis to occur -anode is positive -cathode is negative (electrochemistry)

Photoelectric effect:

Before the Bohr model, it was discovered that If you shine a light of a particular frequency onto a metal plate, some of the electrons from the metal can be knocked loose, creating an electric current. Electrons ejected from the metal are called photoelectrons. The apparatus set up to do this involves: EM radiation, a negatively charged metal plate, a positively charged detector, and an ammeter to measure the current. The plates get positively and negatively charged due to the battery (acts similar to a parallel plate capacitor). *To summarize, the photoelectric effect occurs when light incident upon a metal surface causes electrons to be ejected by that surface. Individual photons provide energy hf to individual electrons, and if that energy is enough to overcome the binding energy of the metal, the electrons get ejected. *the maximum kinetic energy of the ejected electrons is: KEmax= hf - ɸ, where h is Planck's constant, f is the frequency of the photon, and ɸ is the work function (the work function will be given to you. It is diff for diff metals. It's the amount of energy required to free an electron). Based on the wave theory of light, it was expected: 1) a brighter light (higher intensity) would yield more current than a dimmer one. *it was found that brighter light did yield more current, however, light below a certain frequency would not generate any current, regardless of brightness. Thus, to get the photoelectric effect to occur, you must use a certain frequency of light 2) bc light takes time to heat the metal, there should be a delay from when the light first shines on the metal and when the current is detected *No! Current was detected instantaneously when the light illuminated the metal surface 3) if the polarity of the battery were reversed, so that electrons ejected from the metal surface were repelled from the detector, there will be some negative potential at the detector, at which the current drops to zero. This is called the stopping voltage, Vstop. *it was found that the intensity of the light had no effect on the measured stopping voltage, but the frequency of light did affect Vstop *the stopping voltage necessary to prevent the most energetic electrons from reaching a negatively-charged plate is given by: -eVstop = KEmax -This led to the discovery that EM radiation behaves as both a wave and a particle, the discovery of the *PHOTON THEORY*. *EM radiation travels as a wave, but interacts with matter like a particle Wave, intensity=amplitude² particle (photon), v=λf and E=hf (electronic structure)

Does carbon-12 or carbon-13 have 7n?

Carbon-13 has 7n and 6p+ (atomic nucleus)

Units of charge:

Coulomb, C

Diamagnetic vs Paramagnetic:

Diamagnetic: all valence e- are spin paired together in an orbital. No magnetic field, will repel an external magnetic field. For ex, He, Ne, Be, Ca, Zn, Br-, or Sn²⁺ are all diamagnetic. Paramagnetic: all valence e- are not spin paired together in an orbital. Creates a magnetic field, will be attracted towards external magnetic fields. For ex, O, Na, Al, K, Mn, Cr, Cr²⁺ or Cr³⁺ are all paramagnetic. *in paramagnetic objects there is no organization of magnetic fields *way to remember: paramagnetic, the bond is saying "PARA me up with an e-" Ferromagnetic: magnetic fields in an object all align Anti-ferromagnetic: magnetic fields in an object are directly opposite each other; cancel out (electronic structure)

Define total mechanical energy and state the Law of Conservation of Mechanical Energy

E=KE+PE. In the absence of friction, mechanical energy is conserved, KE₁+PE₁=KE₂+PE₂

How strong is the electric field between the plates of a capacitor? How much energy is stored? What is the effect of a dielectric?

E=V/d, where d=distance between the plates. Note, E is uniform. PEelectric=1/2CV² A dielectric increases capacitance

Wave-particle duality:

EM radiation travels like a wave but interacts w matter like a particle. *in general, for all waves, energy is proportional to the square of its amplitude, E∝Amplitude² or intensity∝Amplitude². *for particles, like photons, energy is proportional to frequency, E∝f For EM waves such as light, amplitude and intensity increase the overall energy of waves. However, neither amplitude nor intensity changes the energy per photon. Energy per photon depends on wavelength. The shorter the wavelength (also the higher the frequency), the greater the energy *remember that intensity=power/area= energy per area per time (geometrical optics)

Define electric field. How does the direction of the electric field depend on the sign of the source charge? Give the formula for the strength of an electrostatic field due to a point charge. In what units is electric field strength measured?

Electric field= electric force per unit charge. Field lines point away from + source charges and toward - source charges. At distance r from a point charge of magnitude Q, the electric field strength is E=kQ/r². Electric field has units it N/C

Under what conditions does the ideal gas law give the most accurate results for a real gas?

High T and low P (gas phase)

Give the formulas for the force exerted by, and the elastic potential energy stored in, a stretched or compressed spring

Hooke's Law: F=-kx. PEelastic=(1/2)kx²

Amplitude (oscillations and waves):

How high the peaks are or how low the troughs are, in meters. -the displacement is how far the wave vibrates /oscillates about its equilibrium (center) position -the amplitude is the maximum displacement -amplitude is correlated w the total energy of the system in periodic motion. Larger amplitude = greater or more energy. The amplitude does not depend on frequency, wavelength, or velocity (periodic motion)

Intensity vs Intensity level of a sound:

INTENSITY of a sound= how loud a sound is How loud something sounds (its intensity) corresponds to its power per area (or the rate of energy expenditure per area). Expressed by: I = power/SAsphere, where I is intensity, power=energy/time, and area is the SA of a sphere, 4𝝿r² *units for intensity is W/m² *remember, sounds waves radiate outwards in a circular fashion (like dropping a rock in a pond, creates ripples in an outward circular fashion). *intensity ∝ 1/d², where d is the distance from source. if a wave doubles its distance from the source, it will still spread out over an area that is 2² = 4 times larger, but its intensity will be ¼ the original intensity *intensity ∝ Amplitude², so if you increase the amplitude by 2x, then you increase the intensity by 4x (much louder) INTENSITY LEVEL of a sound= human perception of loudness 𝜷 = 10log I/I₀ where 𝜷 is the sound LEVEL (intensity LEVEL), I is the intensity of a given sound, and I₀ is the threshold of hearing (constant of 1x10⁻¹²) *threshold of hearing: the lowest intensity the human ear can perceive as sound. The threshold of hearing for humans is I₀ = 1x10⁻¹² W/m² *the intensity level (or sound level, 𝜷) has units of bel, B. Usually we multiply this by 10 to get the intensity level in decibels, dB *notice that this equation has log base 10 in it. To solve w/out a calculator: -everytime you multiply I by 10, add 10 to 𝜷 -everytime you divide I by 10, subtract 10 from 𝜷 *for ex, if the intensity is multiplied by 10,000, which is just 1x10⁴ (or 10x10x10x10), the intensity level in decibels is increased by adding 10+10+10+10 = 40 -The decibel system is based on human perception. The decibel value for sound with an intensity of I₀ is zero; below this intensity, sound is not audible. As intensity increases, our perception of its loudness only increases to a much lesser degree. (sound)

Infrared Spectroscopy:

IR, a type of absorption spectroscopy, uses electromagnetic radiation in the IR range. Used to detect functional groups in a molecule. -sample of an organic compound is put inside an IR spectrometer -the sample is irradiated with IR radiation. -if radiation is absorbed by a molecule, this causes intramolecular vibrations and rotations. Covalent bonds will begin to vibrate at distinct energy levels (wavelengths and frequencies). *Vibrations: bonds can stretch, compress and bend like a spring. It is this vibration that is measured in IR-spec. *Rotations: molecules can rotate. Rotations produce waves mainly in the microwave region. However, part of the rotation spectra does overlap with the vibration spectra. -vibrational frequencies are given in terms of wavenumber, ṽ. Wavenumber is the reciprocal of wavelength: ṽ = 1/ƛ Wavenumber is directly proportional to frequency and energy (E=hv). Thus, the higher the wavenumber, the higher the frequency and the greater the energy. Wavenumbers have units of 1/cm or cm^-1 -the IR detector will produce an IR spectra plot, which graphs percent transmittance vs wavenumber. If no IR radiation is absorbed by the molecules in your sample, you will have 100% transmittance (100% of IR radiation hit the detector, none was absorbed). If you have less than 100% transmittance, that means a molecule in your sample must have absorbed IR radiation of a specific frequency (corresponds to a downward dip in your graph). *Transmittance increases as you go up the y-axis. *Where transmittance dips down, that's a region of absorbance. *Wavenumbers decrease from left to right. *Wavenumbers are correlated to frequency. *Peaks toward the left have higher frequency of vibration. Important stretching frequencies: *strength= how much IR radiation was absorbed. Corresponds to a deeper dip in the graph (lower percent transmittance) *intensity= how thick the dip is (it can be sharp/thin or broad/fat). Broad peaks are due to hydrogen bonding (OH and NH). 1)Anything around 3000 and greater cm-1 involves a hydrogen atom. Can be O-H, N-H, or alkyne C-H. OH is the broadest, N-H slightly sharper, alkyne C-H is very sharp. 2)Anything around 2000 cm-1 and below does not involve hydrogen, be it C=O, C=C, C-C, or C-O. The C=C bond is at 1650 cm-1 3)1700 cm-1 is for the carbonyl group. Look for this first. If it isn't present, you can eliminate a wide range of compounds, like aldehydes, ketones, carboxylic acids, acid halides, esters, amides, and anhydrides. 4)below 1300 cm-1 is called the fingerprint region. Patterns in the fingerprint region are unique for each compound just like a fingerprint is unique for each person. *With the same atoms, the higher the bond order, the faster it vibrates, and so the higher the wavenumber. (molecular structure and absorption spectra)

How much volume do ideal gases occupy?

Ideal gases occupy 22.4L per mol of molecules. One mole is made up of 6.02x10²³ molecules. These gazillions of molecules occupy a lot of space, 22.4L. -the volume of an ideal gas does not depend on the identity of the gas. Volume ∝ n Example: 1mol of Ar takes up a volume of 22.4L. 1mol of N2 takes up a volume of 22.4L. (gas phase)

Complementary colors:

If a molecule absorbs light in the visible region, you will see it's complementary color. Complementary color is the color that's on the opposite side of the color wheel. For example, a compound that absorbs blue light will appear to us as orange, since blue and orange are complementary colors on opposite sides of the color wheel. If a substance absorbs: Red light, it will appear green Orange light, it will appear blue Yellow light, it will appear violet *the same is true for the opposite direction, if a substance absorbs green light then it will appear red *pigments absorb a certain color of light and reflect the rest back into your eyes. *Carotene absorbs blue light and reflect the others into your eyes. The absence of blue produces orange-yellowish, the complementary color of blue. (molecular structure and absorption spectra)

Continuity equation:

If a pipe is carrying a liquid, then the flow rate is the same everywhere along the pipe. So, between two points on a pipe, f1=f2, so we get, A₁v₁=A₂v₂, this is the continuity equation -if the tube narrows, the flow speed will increase. If the tube widens, the flow speed will decrease. The flow speed is inversely proportional to the cross-sectional area of the pipe *hydrodynamics (fluids)

Electric potential energy:

If a point charge, q, is moving to a different potential, then it must have a change in electrical PE associated with it *The change in electric PE of a charge q that moves between two points whose potential difference is Δɸ is just given by the product, qΔɸ. *It can also be expressed as qV, where V is defined as the change in potential and is known as voltage. ΔPEelectric = qΔɸ = qVoltage *note: rearranging the equation, we can get Δɸ=ΔPEelectric/q *PE has units of Jewels, J Two main ideas: 1) a negative ΔPE is spontaneous, (moving w nature). So if q is positive → Δɸ=ΔPEelectric/q → Δɸ = -/+ → Δɸ = - ***Positively charged particles, +q, want to accelerate toward lower potential naturally ***positively charged particles, +q, move in the direction of the electric field, E So if q is negative → Δɸ = -/- → Δɸ = + ***Negatively charged particles, -q, want to accelerate toward higher potential naturally ***negatively charged particles, -q, move in the opposite direction of the electric field, E 2) a positive ΔPE is nonspontaneous, (moving against nature). Note: sometimes PE is expressed as U (Electrostatics)

How do you get constructive interference with waves?

If two waves are starting off in phase with each other, (crests of both waves lineup; are 0 degrees or 360 degrees to each other), they will constructively interfere. They will continue to constructively interfere if you change the path length difference by a whole number of wavelengths, for ex, a path length difference of 0, ƛ, 2ƛ, 3ƛ, etc, will allow both waves to perfectly align. If you change the path length difference by an odd half integer number of wavelengths, you will get destructive interference. For ex, a path length difference of ƛ/2, 3ƛ/2, 5ƛ/2, 7ƛ/2 etc, will cause the waves not to align anymore. (light/electromagnetic radiation)

How do you get destructive interference with waves?

If two waves are starting off out of phase with each other, (crest of one wave meets trough of the other wave; phase shifted; are 180 degrees to each other), they will destructively interfere. They will continue to destructively interfere if you change the path length difference by a whole number of wavelengths, for ex, a path length difference of 0, ƛ, 2ƛ, 3ƛ, etc, will allow both waves to be out of alignment with each other. If you change the path length difference by an odd half integer number of wavelengths, you will get constructive interference. For ex, a path length difference of ƛ/2, 3ƛ/2, 5ƛ/2, 7ƛ/2 etc, will cause the waves to align. (light/electromagnetic radiation)

If you throw a ball into the air, when does the force of your throw stop acting on the ball?

Immediately when the ball leaves your hand (Force)

Heisenberg Uncertainty Principle:

In the wave-particle duality of light, there is uncertainty with position and momentum of an ejected electron. If you know the momentum, you don't know the position. If you know the position of the electron, you don't know it's momentum. This is expressed by: ΔxΔp ≥ h/2𝛑, the electron's position Δx, and the momentum Δp, must be greater than or equal to plank's constant divided by 2pi. The uncertainty in position and momentum are inversely proportional to each other (if you increase one you decrease the other). For ex, if your electron is at a position 2 with a momentum of 2, then (2)(2)=4. If you decrease the uncertainty of the position to 1 then you increase the uncertainty in the momentum to 4, (1)(4)=4. *this happens bc h/2pi is a constant. (electronic structure)

The dynamics of simple harmonic motion of a spring:

Includes force and energy, (remember, dynamics is concerned with the motion of objects in relation to the physical factors that affect them: force, mass, momentum, energy, etc) -Force= the spring exerts a force on the block. This is given by Hooke's Law, F=-kx -Energy= the spring has elastic potential energy, given by PE=1/2kx². The block has kinetic energy, given by KE=1/2mv². Elastic PE and KE transfer back-and-forth between each other. Since work is energy, W by spring= -ΔPE, W against spring= +ΔPE. (periodic motion)

The kinematics of simple harmonic motion of a spring:

Includes period and frequency, (remember, kinematics is the description of motion in terms of an object's position, velocity, and acceleration) -Period, T=2𝞹 √m/k OR ω=√k/m -Frequency, f=1/2𝝿 √k/m (periodic motion)

Real images have orientations that are always ______.

Inverted (geometrical optics)

What is the job of a battery?

It is a voltage source! Works to maintain a potential difference (voltage) between its terminals. The value of voltage is denoted by V or sometimes ɛ for emf. A voltage is needed to create a current. *the battery terminal that's at the higher electric potential is denoted by a longer line and called the positive terminal. The terminal that's at the lower electric potential is denoted by the shorter line and called the negative terminal. Remember, the direction of current is taken to be the direction that positive charge flows. Thus, current, (I), always flows from the positive terminal of the battery to the negative terminal of the battery. (Circuit Elements)

How is the change in gravitational potential energy affected by the path taken by the object?

It isn't. All that matters is the initial and final positions, not the actual path taken

Electric force vs electric field:

It takes two charges to create an electric force, but it only takes one charge (the source charge) to create an electric field. *electric force is given by Felectricalonq *electric field is given by E (Electrostatics)

All types of energy have the same unit. This is the _____.

Joule (energy of point object systems)

Units of energy:

Joule, J Note: kgᐧm²/s² = J = Nᐧm 1N= kgᐧm/s²

Converting from C to K:

K = C + 273 (gas phase)

Freezing point of water/melting point of ice:

K= 273 C= 0 F= 32 (gas phase)

Room temperature:

K= 298 C= 25 F= 77 (gas phase)

Body temperature:

K= 310 C= 37 F= 98.7, app 99 (gas phase)

BP of water/condensation of steam:

K= 373 C= 100 F= 212 (gas phase)

Conductor:

Materials in which charges can move freely. Examples of conductors = metal elements or a solution that contains lots of dissolved ions (such as saltwater) *In a metal, one of more valence electrons are not strongly bound, and are thus free to roam. If a metal is placed in an electric field, these free charges (called conduction electrons) will move in response to the field. Note: a conductor as a whole is electrically neutral in charge. It is just able to separate charges. One end will be positive and one end will be negative **any net charge on a conductor resides on its surface. Since there's no electrostatic field inside a conductor, you can block out external electric fields simply by surrounding yourself w metal. The free charges in the metal will move to the surface to shield the interior and keep E=0 inside (Electrostatics)

Units of acceleration:

Meter per second squared, m/s²

Units of speed:

Meter per second, m/s

Can total internal reflection occur for a beam of light traveling from air to water?

NO! A beam of light incident traveling in the air and striking the surface of water can never experience total internal reflection bc n1 < n2. In other words, there'll be some reflection and some refraction. Some of the light's intensity will be transmitted into the water. (geometrical optics)

The capillaries are much smaller than the aorta, so is the blood flow in them faster?

No. Blood flow in capillaries is not any faster than blood flow in aorta. This is bc aorta splits into tons of capillaries. Therefore the total cross sectional area carrying blood is the same (circulatory system)

Can sound be produced in a vacuum?

No. Sounds waves are mechanical waves, thus sound is produced by vibrations in a medium. Vibrations produce pressure waves that oscillate parallel to the direction of propagation. Sound cannot be produced in a vacuum, nor can sound travel across a vacuum. (sound)

If two equal but opposite forces act on an object, can they constitute an action-reaction pair?

No. The two forces in an action-reaction pair always act on different objects (one acts on Object 1, the other back on Object 2)

Describe the work done by normal force:

Normal force usually does zero work. Fn is usually perpendicular to motion. Cos(90)=0 (Work)

A charged capacitor has charge Q, and the voltage between the plates is V. What will happen to C if Q is doubled?

Nothing. For a given capacitor, C is a constant. Bc Q=CV, we see that Q is proportional to V. Doubling Q will cause V to double. (Circuit Elements)

When you add increasing amounts of solute, what happens to the osmotic pressure?

Osmotic pressure is a colligative property. When you add more solute, OSMOTIC PRESSURE ELEVATION occurs. More solute, higher osmotic pressure. "Water follows solute." Osmotic pressure determines whether and in what direction osmosis will occur, (where water will flow). (gas phase)

Properties of vapor pressure:

Pvap is the force exerted by the gas particles that vaporize from a liquid or solid sample. The Pvap is the pressure exerted when the molecules leave the surface at the same rate as they return -More gas particles = more force on the walls of the container = higher vapor pressure 4 main properties: 1)external P has no effect on Pvap *for ex, if your at sea level and have a container w liquid and a certain Pvap, the Pvap would be the same if you took the container to the top of Mt.Everest 2)external T is directly proportional to Pvap, T∝Pvap 3)intermolecular forces are indirectly proportional to Pvap, IMF∝1/Pvap *more intermolecular forces=lower Pvap. Less intermolecular forces=higher Pvap, the molecules can more easily escape from the surface of the liquid 4)bp is indirectly proportional to Pvap *if something has a high bp, that means at a given temp less molecules will be in the gas phase, so a lower Pvap SUMMARY: Pvap∝T∝1/IMF∝1/BP Additional info: -Pvap is a property of liquids and solids... Not gases! For ex, can occur with solids (sublimation) or liquids (vaporization) -a substance w a high vapor pressure at normal temperature is often referred to as volatile -at the temperature of liquid increases, the KE of its molecules also increases. As the KE of the molecules increase, the number of molecules transitioning into a vapor also increases, thereby increasing the vapor pressure (gas phase)

A capacitor has a capacitance of 2nF. How much charge can it hold at a voltage of 150V?

Q=CV → (2x10⁻⁹ F)(150V) → 3x10⁻⁷ C (Circuit Elements)

Two people are pushing on a 1m door, one trying to open it and the other trying to close it. The person attempting to close the door is pushing on the end w a force of 50N. If the person attempting to open the door is pushing in the middle and the door remains motionless, which what force is the person attempting to open the door pushing? A)12.5N B)25N C)50N D)100N

Since the door is not moving, torque1=torque2 Since force is directed at a 90 degree angle to the door, 𝛕=rF So, r₁F₁=r₂F₂ → (1m)(50N)=(.5m)(F₂) **without even doing any math, we see that F₂ must be larger than F₁ Answer = 100N (Equilibrium)

The density of water in the solid form is _____.

The density of water in the solid form (ice) is less dense than than the density of water in the liquid form. Why ponds freeze on the top layer, while bottom layer is still liquid (allows aquatic life to survive!). Or, why ice floats in your cup of ice water. *density of H2O(s) < density of H2O(l) > density of H2O(g)

How do you calculate the wavelength or energy emitted or absorbed when an electron changes energy levels?

The wavelength of the emitted or absorbed radiation is governed by the Rydberg Formula, 1/ƛ = R(1/nfinal² - 1/ninitial²), where R is the rydberg constant, n final is the final energy level, and n initial is the initial energy level. You do not need to memorize this equation, it will be given to you. Just know how to use it The energy of the emitted or absorbed radiation is: E=hf=hc/ƛ, where E is energy, f is frequency, and c is the speed of light. *energy is emitted for transitions to lower energy levels (n final < n initial) *energy is absorbed for transitions to higher energy levels (n final > n initial) Photons absorbed or emitted by a H atom: E=hf=|13.6eV (1/nfinal^2 - 1/ninitial^2)| (atomic nucleus)

What is true about the work done by kinetic friction? By a centripetal force?

The work done by kinetic friction is always negative (since the angle between Ffrictionstatic and displacement is 180 degrees). The world done by a centripetal force is always zero (since the angle between Fcentripetal and displacement is 90 degrees)

Define total internal reflection. When does it occur?

Total internal reflection occurs when a beam of light striking a boundary does not transmit through to the next medium; it happens when the light strikes the boundary of a medium w a lower refractive index (n₂<n₁) at an angle of incidence greater than the critical angle, θcritical=sin⁻¹(n₂/n₁)

Bernoulli equation:

Total mechanical energy is conserved for ideal fluid flow. Density within all parts of an ideal fluid is the same. Expressed by: P₁ + ½ ⍴v₁² + ⍴gy₁ = P₂ + ½ ⍴v₂² + ⍴gy₂ *similar to equation for conservation of total mechanical energy, KE+PE = KEf+PEf *hydrodynamics (fluids)

Work-energy theorem:

Total work done on an object (w no change in other forms of energy) is equal to its change in KE. This is expressed by: Wtotal=ΔKE -this formula gives you another way to calculate work. If you know the change in an object's KE, then you can calculate the amount of work that was done on it, w/out knowing the force or displacement -work can be thought of as a transfer of energy -if total work=0, then the object's KE remains the same -negative work done on an object transfers energy from the object to the environment. Thus, decreasing its KE, and decreasing its speed. -positive work done on an object transfers energy from the environment into the object. Thus, increasing its KE, and increasing its speed. **Work on an object can transform into KE: -when you push on an object, it will move: Fd = 1/2mv² -when gravity does work on an object, it will move: Fweightᐧh = 1/2mv² → mgh = 1/2mv² **KE of an object can do work: -a moving object can slide up an inclined plane before coming to a stop, 1/2mv²=mgh -a moving object can slide against friction for a while before coming to a stop, 1/2mv²=Ff(displacement) (Work)

Ultraviolet/Visible Spectroscopy:

UV/Vis, a type of absorption spectroscopy, uses electromagnetic radiation in the UV and visible range. -sample of an organic compound is put inside the UV/Vis spectrometer -the sample is irradiated with UV radiation and visible light radiation, photons. Pi-electron and non-bonding electron transition: *Every time you have a bond, the atoms in a bond have their atomic orbitals merged together to form molecular orbitals. *Every time you have molecular orbitals, you get bonding molecular orbitals and non-bonding and/or anti-bonding orbitals. *Normally, electrons sit in their bonding orbitals because it is the most stable there. If bonding orbitals are full, then non-bonding orbitals are occupied. *Given enough energy (as in absorption), the electrons transition from the bonding or non-bonding orbitals to the anti-bonding orbitals. *If too much energy is absorbed, enough electrons escape the bonding orbitals enter the anti-bonding orbitals to break the bond completely. *For UV absorption, we're not worried about breaking bonds. We're only interested in the pi-electrons of double bonds because their molecular orbital transitions result in UV absorption. *Double bonds absorb UV because the pi electrons transition from the bonding and non-bonding molecular orbitals to the anti-bonding orbitals. Conjugated systems: *Conjugated systems decreases the energy of electromagnetic radiation that is absorbed. *The more conjugated double bonds there are, the longer the wavelengths of absorbed radiation. *If there are enough conjugated double bonds, the molecule will start to absorb in the visible region. Summary- if compounds in the sample absorb UV radiation: -ground state pi-electrons of double bonds become excited, moving from bonding and non-bonding molecular orbits to antibonding orbitals -compound will be clear/colorless (only absorbing UV radiation, all of the visible wavelengths will be reflected) -UV falls in the range of 190-380nm Summary- if compounds in the sample absorb visible light (a photon): -ground state pi-electrons of double bonds become excited, moving from bonding and non-bonding molecular orbits to antibonding orbitals -visible light is absorbed by the molecule, so it will be some color (the color a compound maximally absorbs is complementary to the color it will appear to our eyes) -occurs in highly conjugated organic compounds -visible region falls in the range of 380-750nm Compounds that absorb UV/Vis radiation will be displayed on an Absorption Spectrum *graphs the absorbance vs wavelength in nm, with smaller wavelengths being UV light. *Wavelength of maximum absorption, ƛmax= place on graph with highest absorbance. Will correspond to a particular wavelength of light. The more extensive the conjugated system is, the longer the wavelength of maximum absorption will be, ƛmax, (more conjugation leads to absorption in the visible region instead of the UV region). (molecular structure and absorption spectra)

A balloon holds a mixture of fluorine, F2(g) and helium, He(g). If the rms speed of helium atoms is 540 m/s, what is the rms speed of the fluorine molecules?

Using Graham's Law: velocity fluorine/velocity He = √ molar mass He/molar mass fluorine → velocity fluorine/540 = √4/38 → velocity fluorine/540 = √ 1/9 → velocity fluorine/540 = ⅓ → 180m/s (gas phase)

When an electron orbiting a proton falls from the n=2 shell to the n=1 shell, what is the sign of the work done by the electrostatic force?

W=Fdcosθ, force is directed towards the nucleus, displacement is moving towards the nucleus. Since F and d are in the same direction, we have positive work. *could also be thought of as W= -ΔPE, since the electron is moving towards the nucleus, PE is decreasing, thus -(-ΔPE) → +W (Electrostatics)

EM radiation can behave as a _____ or as a ______.

Wave Particle, called a photon **this is the wave-particle duality of light; quantum physics (light/electromagnetic radiation)

Mass number:

Written form: the mass number, A, is the number of protons + neutrons in the nucleus of an atom. If we let N stand for the number of neutrons, then A = Z + N **the mass number determines the isotope (atomic nucleus)

What happens to weight when you are further away from the earth?

You weigh less when you are further away from the earth bc the force of gravity decreases w distance. However, you are not truly "weightless" when orbiting the earth in space. You are simply falling toward the earth at the same rate as your space craft *you gain weight as you fall from space to the surface of the earth *for a given mass, its weight on earth is diff from its weight on the moon (Force)

Young's double slit experiment:

a coherent light source, such as a laser beam, illuminates a plate pierced by two parallel slits, and the light passing through the slits is observed on a screen behind the plate. You would expect that there would be two bright regions on the screen in the same shape as the slits. However, the wave nature of light causes many bright and dark bands on the screen. *when a wave encounters a hole or a corner, it spreads out. This is called diffraction (bending/spreading out of a wave). Light spreads out after passing through the slit, instead of going in a straight line *the waves from each hole will begin to interfere. Constructive interference (peak meets peak) results in bright bands (greater intensity of light). Destructive interference (peak meets trough) results in no bands/dark bands. *this causes a very bright band directly in the center of the two slits. Bright bands decrease in intensity (become less bright) as you move out outward. *in the middle of bright and dark bands, there is bands with intermediate brightness. This is where waves are somewhere between destructive and constructive interference. *waves started out in phase, so constructive interference will occur when the path length difference traveled by the two waves is 0, ƛ, 2ƛ, 3ƛ, etc, allowing both waves to perfectly align. If the path length differs by an odd half integer number of wavelengths, you will get destructive interference. For ex, a path length difference of ƛ/2, 3ƛ/2, 5ƛ/2, 7ƛ/2 etc, will cause the waves not to align anymore (this is where no bands/dark bands are) *Young's double slit equation is: dsinθ=mƛ, where d is the distance between the two slits, θ is the angle from the center line up to a point on the wall where constructive interference is occurring, m is the path length difference, ƛ is the wavelength (the distance between peaks) Note: sometimes m is called the "order" of the constructive points. Zeroth order means path length is zero wavelength difference (both waves travel the same distance), first order means path length is one wavelength difference, second order means path length is two wavelength difference, etc *bright bands occur at m= 0, +/-1, +/-2, etc *dark bands occur at m= +/-0.5, +/-1.5, +/-2.5, etc In order for interference to occur, the following conditions must hold: -the interfering light source must be coherent. This means they must constantly maintain the same phase relationship (one wave can't be getting a longer wavelength, while the other wave is getting a shorter wavelength). The light coming from Young's double slit experiment are coherent bc a single light source shines through both slits -the light source must be monochromatic (of single color/wavelength; like a laser) (light/electromagnetic radiation)

Capacitor:

a component that is able to store electric charge, Q, and store energy, (PEelectric) *It consists of two plates of a conducting material, (like a metal), separated by a dielectric, (like paper) *when the capacitor is connected to a battery, electrons from one plate will flow towards the positive terminal of the battery. Electrons then travel through the battery, they then get repelled from the negative terminal of the battery, ending up at the other plate. This creates a charge difference → One piece of metal (who is losing electrons) becomes positively charged, while the other piece of metal (who is gaining electrons) becomes negatively charged. Both pieces of metal have the same magnitude of charge (for ex, if one plate has a charge of +6C, then the other plate has a charge of -6C). Even if the two plates were different sizes or shapes, they would still store equal and opposite amounts of charge. One plate is just losing electrons, while the other plate is gaining electrons. *eventually, the piece of metal who was losing electrons becomes very positively charged. Electron's no longer want to flow to the positive terminal of the battery bc the plate their on is already positive. So, the movement of electrons stops. The accumulated charge difference on the two plates just sits there. *this explains why a dielectric is necessary. If the plates were touching, electrons would flow, and they would never store electric charge. You would just have a circuit. *so a capacitor is something that stores charge. But, not all capacitors store the same amount of charge. One capacitor hooked up to a battery might store a lot of charge, while another capacitor hooked up the same battery stores a tiny amount of charge. The capacitance of a capacitor tells you how well it will store charge. -capacitor w a high capacitance will store a lot of charge -capacitor w a low capacitance will store a little charge C=Q/V, the capacitance equals the magnitude of the charge of one plate on the capacitor (in coulombs) divided by the voltage (in volts). The voltage is just the potential difference between the two plates. The positively charged plate is an area of high electric potential. The negatively charged plate is an area of low electric potential. *if you let a battery fully charge a capacitor, the voltage across the two plates of the capacitor equals the voltage across the terminals of the battery *the capacitance does not depend on Q or V. If Q increases, V increases. So, the proportion remains constant, and C remains unchanged. *capacitance has units of coulomb/volt, which is the farad Ex: a 2 farad capacitor stores a charge of 6 coulomb's, what is the voltage? 2F= 6C/V → 3 volts is the voltage *after a capacitor is charged, it can be hooked up to a lightbulb. This completes the circuit! Electrons flow through the circuit, and the PEelectric that was stored in the capacitor comes out as light and heat through the lightbulb. *once the capacitor discharges itself, (there are no more electrons to transfer), the lightbulb will stop shining. (Circuit Elements)

Current in a straight wire:

a current in a wire is just the movement of electrons. Thus, it has a magnetic field. The magnetic field lines wrap around the the wire, forming closed loops. *remember, by convention, the direction of current is defined as the direction of moving positive charges. *to find the direction of the magnetic field lines, use your right hand and point your thumb in the direction of current, I. Whichever way your fingers wrap around is the direction of the magnetic field lines. Palm gives the direction of F for a positive charge. Back of hand gives direction of F for a negative charge *the magnitude of the magnetic field created by a straight wire carrying a current I is proportional to I and inversely proportional to the distance r from the wire. Expressed by: B ∝ I/r, the magnetic field will be stronger if the current is increased or if we are positioned closer to the wire *two wires will attract each other if the current is in the same direction *two wires will repel each other if the current is in opposite directions (Magnetism)

Concentration Cells:

a galvanic cell that has identical electrodes but which has half-cells w different ion concentrations. Since the electrodes and relevant ions in the two beakers have the same identities, the standard cell voltage, E°, would be zero. But such a cell is not standard bc both electrolytic solutions in the half-cells are not 1M. So, even though the electrodes are the same, in a concentric cell there will be a potential difference between them, and an electric current will be produced. For ex, let's say that both electrodes are made of zinc, and the Zn²⁺ concentrations in the electrodes are 0.1M and 0.3M. Electrons will be induced to flow through the conducting wire to the half-cell w the higher concentration of these positive ions. So the zinc electrode in the 0.1M solution would serve as the anode, with the liberated electrons flowing across the wire to the zinc electrode in the 0.3M solution, which serves as the cathode. When the concentrations of the solutions become equal, the reaction will stop. (electrochemistry)

Work:

a measure of how much a force contributes to the displacement of an object. The work done by a CONSTANT FORCE is expressed as: W = Fdcosθ, where θ is the angle between F and d. -work is energy, and the unit is the Joule, J. 1 J = Nᐧm = kgᐧm/s² ᐧm = kgᐧm²/s² -if the force is not constant, the work equation cannot be used -work is a scalar quantity. It can be positive, negative, or zero, but has no direction. -if the force applied and the displacement is in the same direction, work is positive. Ex, pushing a crate across a rough terrain involves you doing positive work (you are pushing forward and the crate is moving forward) -if the force applied and the displacement is in the opposite direction, work is negative -if force is parallel to displacement, the work done by F is just W=Fd -if force is perpendicular to displacement, then work done by F is zero, cos(90)=0, no work is done. For ex, no work is done by your arms when you carry a bucket of water for a mile. The displacement of the bucket is moving horizontally, while you apply a force vertically, at 90 degrees. -if the angle is greater than 0 degrees but less than 90 degrees, (0 degrees < θ < 90 degrees), then positive work is done -if angle is greater than 90 degrees but less than 180 degrees, (90 degrees < θ < 180 degrees), negative work is done (Work)

Parallel plate capacitor:

a pair of parallel metal plates that can hold equal but opposite charges. The plate connected to the positive terminal of the battery becomes positively charged, while the plate connected to the negative terminal of the battery becomes negatively charged. Charge will stop flowing when the potential difference between the plates (the voltage) matches the voltage of the battery. *Notice that one plate carries a positive charge and the other plate carries a negative charge, but the net charge on the capacitor is zero. However, when we talk about the charge on a capacitor, we always mean the magnitude of the charge on either plate, which is +Q. *if V is the potential difference between the plates of a charged capacitor (voltage), and Q is magnitude of the charge of the capacitor, then Q and V are proportional. The proportionality constant, C, is called the capacitance. Capacitance has units of farad, F. C=Q/V *the capacitance does not depend on voltage or charge. The capacitance only depends on the area of the plate (plate size) and distance between the plates *if you increase the magnitude of charge on each plate, Q, then you increase the potential difference between the two plates, V. The proportion Q/V does not change, thus the capacitance stays the same. For a given capacitor, C is constant. *if you graph Q vs V, the slope of the line is C *the capacitance measures a parallel plate capacitor's "capacity" for holding charge at a certain voltage. A capacitor with a greater capacitance can hold more charge per volt. *the capacitance of a parallel plate capacitor WITH NO dielectric: C=ɛ A/d, where ɛ is the permittivity of free space (8.85x10^-12 F/m), A is the area of each plate, and d is distance between the plates. Capacitance has units of farad, F. Coulomb per Volt. *greater capacitance is created by a greater plate area, A, or smaller distance between the plates, d. (Circuit Elements)

Voltage:

a potential difference between two points, V=Δɸ. It is a voltage that creates current (the movement of charge). Remember, negative charges (conduction electrons) always move toward higher electric potentials. If there's no voltage (no potential difference), then the conduction electrons will just zoom around their original positions, going essentially nowhere; there will be no current. *often, the voltage that creates a current is referred to as electromotive force (emf, ɛ). The emf is really not a force; it's a voltage *a battery is a source of emf *if a battery has no internal resistance, then potential difference across the battery = emf *if a battery has internal resistance, then potential difference across the battery = emf - voltage drop due to internal resistance (Circuit Elements)

Wave speed:

a wave will travel at a speed of, v=ƛf, where v is velocity in m/s, ƛ is the wavelength in meters, and f is the frequency in hertz (periodic motion)

Give the approximate infrared stretching frequencies for the following functional groups: a) O-H b) C=O c) C=C

a) O-H, 3200-3600 cm⁻¹ b) C=O, 1700 cm⁻¹ c) C=C, 1650 cm⁻¹

White light is:

all colors of the spectrum are getting reflected off an object. The object absorbs no visible light. (geometrical optics)

Capacitors in series:

all have the same charge (similar to resistors in series all having the same current), but the equivalent capacitance is found by using the same formula we used for resistors in parallel, Ctotal = C₁C₂ / C₁ + C₂, you can only do two capitances at a time (Circuit Elements)

Capacitors in parallel:

all have the same voltage (like resistors in parallel), but the equivalent capacitance is the sum of the individual capacitances (like resistors in series), Ctotal = C1 + C2 + C3 ... (Circuit Elements)

In mass spectrometry, what if the high energy electrons not only ionize but also fragment your molecule?

all the fragmented ions will be detected and plotted in the mass spectra. (molecular structure and absorption spectra)

Rotational inertia:

also known as the "moment of inertia." An object's rotational inertia, I, tells you how resistant an object is to rotational acceleration, denoted by ⍺. note: rotational acceleration is not the same as centripetal acceleration. Rotational acceleration is when something is moving in a circle and speeding up or slowing down. Centripetal acceleration is related to the centripetal force, which is directed towards the center of the circle. -a torque is required to produce rotational acceleration, just as a force is required to produce translational acceleration. The rotational analog of the equation Fnet=ma is 𝞽net = I⍺. The torque is to rotational motion what force, Fnet, is to translational motion. Similarly, rotational inertia, I, is to rotational motion what translational inertia (mass) is to translational motion. In general: -a mass closer to the rotational axis gives a smaller I. Easier to rotate. -a mass farther from the rotational axis gives a larger I. More difficult to rotate. (Equilibrium)

Molecular orbital theory:

an atom takes its atomic orbitals and hybridizes them into molecular orbitals when a covalent bond is formed. In other words, molecular orbitals are obtained by combining the atomic orbitals. Molecular orbitals are lower in energy. Atomic orbitals → molecular orbitals *includes bonding MO, non-bonding MO, and antibonding MO For ex, H + H → H2, here, each H has one electron in their s orbital, 1s1. When they form a bond, a sigma bonding molecular orbital, σ, and sigma antibonding MO, σ*, are made. The two electrons reside in the bonding MO, which is lower in energy than the antibonding MO. If an electron were to become excited, it can jump from the boding MO to the antibonding MO. -sp3 hybridized carbon: If an atom is participating in multiple bonds, it will utilize hybrid orbitals to form them. For ex, CH4, where carbon is making 4 bonds, it will take its 2s orbital and its three 2p orbitals to create four sp3 hybridized molecular orbitals. In order for this to occur, carbon must move one of its 2s electrons up to the empty 2p orbital. This allows for hybridization, creating four MO's that are equal in energy (degenerate). The extra electron is added to each of the four MO's by the four hydrogens when the covalent bond is formed -sp2 hybridized carbon: when carbon participates in a db, for ex, C2H4, during bond formation each carbon will promote one of it's 2s electrons to the empty 2p orbital. Three orbitals will be hybridized and lower in energy, sp2, while one p orbital will be left unhybridized and thus be higher in energy. Due to this, each unhybridized p orbital on the two carbons will overlap to form a pi bond. *in order of increasing energy, σ < 𝜋 < 𝜋* < σ* (molecular structure and absorption spectra)

Ideal gas:

an ideal gas consists of molecules moving around randomly colliding w one another and w the container wall. The ideal gas obeys the kinetic molecular theory of gases. The kinetic theory holds the following assumptions: 1)random molecular motion 2)no intermolecular forces 3)no (negligible) molecular volume. The volume of the individual particles of an ideal gas is negligible compared to the volume of the gas container 4)perfectly elastic collisions (conservation of total kinetic energy) The kinetic theory holds the following concepts: 1)pressure of a gas is due to its molecules constantly colliding w the walls of the container (elastic collisions). Pressure is equally distributed over the walls of a container bc molecular motion is random 2)has an average KE proportional to its temperature. Higher temperature means the molecules are traveling faster, lower temperatures means slower molecules -you can treat gases as ideal at: Low pressures, High temp *at these conditions, interactions of the particles are minimized -deviations from ideal occurs at: high pressure, low temps -ideal gases behave according to the ideal gas law, PV=nRT, where P is pressure in atm, V is volume in L, n is moles, R is the gas constant (0.08 Lᐧatm/Kᐧ mol), and T is temp in kelvin (gas phase)

What are the five periodic trends?

atomic size first ionization energy electron affinity electronegativity acidity/basicity

Momentum:

can be thought of as "mass in motion." All objects have mass; so if an object is moving, then it has a linear momentum. It is expressed as: p=mv, with units of kgᐧm/s -momentum is a vector, it has direction. Can be a positive or negative value -the more momentum something has, the harder it is to stop -a large boulder-rock rolling down a mountain has more "oomph" (hard to stop, tons of momentum!) vs a tiny pebble rolling down a mountain. -a meteorite falling from space has a very very high velocity. Even though it may be small, when it lands on earth it will cause damage. The meteorite has tons of momentum. -a motorcycle, with its small mass, is easier to stop (has less momentum) compared to a semi-truck, with its huge mass, harder to stop (has tons of momentum) (Equilibrium)

Centripetal force vs Centripetal acceleration:

centripetal force is due to centripetal acceleration. Centripetal acceleration is due to changes in velocity when going around a circle. The change in velocity is due to a constant change in direction Centripetal force, Fc = ma = mv²/r. *It is also sometimes written w a negative sign to indicate that the direction of the force is toward the center of the circle Centripetal acceleration, ac = v²/r -the direction of both the centripetal acceleration and centripetal force are directed towards the center of the circle -the tension force in the string (attached to the object going in circles) is the same as the centripetal force -when the centripetal force is take away (such as when the string snaps), the object will fly off in a path tangent to the circle at the point of the snap -an object undergoing uniform circular motion is continually being acted upon by the centripetal force. So, why does the object not fall into the center of the circle? Bc of the object's speed, it remains in a circular orbit around the center. Fc points toward the center of the circle. This tells the velocity, say at position 1, to move downward a little, so that at the next moment, at position 2, the velocity will point downward slightly. This is what we want in order to keep the object traveling in a circle! If the centripetal force were suddenly removed, then the object's velocity wouldn't be slightly pulled downward anymore, and the object would not move in a circle anymore. It would move in a straight line, tangent to the circle at the point where the force was removed. (Force)

Empirical formula vs molecular formula:

empirical formula is what you get after dividing everything in the molecular formula by the highest common factor Ex: molecular formula = C6H12O6 Empirical formula = CH2O

Law of gravitation:

every object in the universe exerts a gravitational pull on every other object. The magnitude of this gravitational force is proportional to the product of the object's masses and inversely proportional to the square of the distance between them. The constant of proportionality is denoted by G and known as "newton's universal gravitational constant." Given by: Fgrav= G Mm/r² *do not have to know value of G, it will be given -inverse square law. The magnitude of the gravitational force is inversely proportional to the square of the distance between the objects. If the distance increases two fold, gravity decreases by a factor of four -the "distance" is the distance of mass between the two objects -gravity is the weakest of the four universal forces. This weakness is reflected in the universal gravitational constant, G, which is orders of magnitude smaller than the Coulomb's constant *note: Coulomb's law (for the electrostatic force between two charges) is also an inverse square law -with this law, if Fw=Fg=mg, then we get g=G M/r². Allows you to calculate g! (Force)

When you add increasing amounts of solute, what happens to the fp?

fp is a colligative property. When you add more solute, FP DEPRESSION occurs. Solute gets in the way and prevents liquid from freezing into a nice lattice structure, thus FP decreases. FP depression, ΔT = -k i m *ΔT gives you the change in freezing temp, k is the solvents fp depression constant, i is the solutes van't hoff factor, m is the molality of the solution *water has a fp depression constant, k, of approximately 2 *molality, m= mol solute/kg solvent -remember, fp and mp mean the same thing. When you add more solute, fp decreases (harder to freeze something) and mp decreases (easier to melt something) **wants to stay a liquid (gas phase)

Though the total length of all pathways of the human circulatory system is on the order of 10^8 m, a typical RBC may complete a circuit of about 3 meters in one min. What is the total distance traveled by the RBC in one hour? What is its total displacement in that time?

if 3m are traveled in one min, then (3m/min)(60min/hour) → 180m will be traveled in an hr displacement is the net change in position. If a circuit is completed, the displacement is 0m. (translational motion)

What happens to an object's velocity v if its acceleration is in the same direction as v? opposite v? perpendicular to v?

if a and v are in the same direction, speed will increase; if a and v are in opposite directions, speed will decrease; if a is perpendicular to v speed will not change (but direction of velocity changes)

State the law of conservation of momentum

if no external force acts, then total momentum is conserved in a collision, ptotalbefore = ptotalafter

Combined gas law:

if the amount of moles of a gas remains constant (no change in n), then nR is constant. So, PV/T must also be constant. P₁V₁/T₁ = P₂V₂/T₂ -Boyles, Charles, and Gay-Lussac's law can be derived from the combined gas law (gas phase)

Coulomb's Law:

if two charges are a distance r apart, then the electrical force between them, (Felectrical) is directed along the line joining them. The magnitude of the force is proportional to the charges (q1 and q2) and inversely proportional to r². Expressed by: Felectrical = k |q1q2| /r² *where k is the proportionality constant, its value depends on the material between the particles (on the mcat, usually particles are separated by empty space (air). So, k is often denoted as k₀ and called the COULOMB'S CONSTANT. Where k₀= 9x10⁹ Nᐧm²/C²). Note, that q1 and q2 are the charges in Coulombs, and r² is the distance between the objects *like any force, the electrical force is given in units of newtons, N -often q1 and q2 will be given in 𝜇C or nC. These are smaller numbers to deal w bc one coulomb is a lot of charge! In general, 1𝜇C=10⁻⁶ C and 1nC=10⁻⁹ C -remember, coulomb's law is just an inverse square law Felectical∝1/r² -the absolute value sign in the formula gives the magnitude of the force, whether repulsive or attractive. If direction, + or - needs to be assigned, it should be done based on the fact that like charges (two positives or two negatives) repel each other, and opposite charges (one positive and one negative) attract. *if the charges have the same sign, the force is repulsive *if the charges have the opposite signs, the force is attractive (Electrostatics)

Mass deficit vs binding energy:

if you look at the precise mass of a proton it is 1.00727 amu, a neutron is 1.0086 amu, and an electron is 0.00054 amu. So, you would think that if you have a Helium atom, since it has 2p+, 2n, and 2e-, it should have a total mass of 4.032980 amu. However, when you do this in lab and measure the mass, you get a slightly different value, 4.002603 amu. This is known as the MASS DEFICIT, ΔM. Which, here, is 0.03037amu. The mass of the individual constituents which makeup an atom (p+, n, e-), is always greater than the mass when these constituents are put together in an atom. That is, Mnucleons > Matom Mnucleons - Matom = mass deficit (also called mass defect) = ΔM. *where Mnucleons is the mass of all the nucleons that make up the atom in their free unbound state, and Matom is the mass of the atom. *when you shove p+, n, and e- together in an atom, some of the mass is lost. This mass is turning into energy. The energy that makes up for the mass deficit is calculated by E=mc^2, where E is energy, m is mass in kg, and c is speed of light *when you break an atom apart, energy must be put into the system to regain mass. This energy is called the BINDING ENERGY -binding energy= the energy (work) required to separate a nucleus into its individual constituents (p+, n, e-). The bigger the atom, the bigger the nucleus, thus more binding energy. Binding energy = converting ΔM into its equivalent in energy = ΔM c². The conservation of mass and energy: the total mass and energy before a reaction is always the same as the total mass and energy after the reaction. *If the total mass before the reaction is different from the total mass after the reaction, then the difference in mass is made up for by energy. *Energy is liberated when mass is lost during a reaction (forming a nucleus) *Energy is absorbed with mass is gained during a reaction (breaking a nucleus) Energy liberated = binding energy. And finally, Mnucleons = Matom + binding energy/c² (atomic nucleus)

In the electrochemical cell described by the following cell diagram, what reaction occurs at the anode? Zn(s) | Zn²⁺ (aq) || Cl-(aq) | Cl₂(g)

in any electrochemical cell, oxidation occurs at the anode. So, since Zn is present at the anode, Zn must be getting oxidized Zn → Zn²⁺ + 2e- (galvanic cell) (electrochemistry)

Single slit:

interference is, by definition, when multiple waves overlap. When a plate has a single-slit, we still get interference. Why? Huygen's Principle: every point on a wave front can be thought of as a source of another wave that spreads out spherically. In other words, a wavefront can be thought of as an infinite source of waves. A wave is always diffracting/spreading out. We just notice it when there is a single slit bc some sources of waves on the wavefront get blocked, while others don't. *light shining through a single slit casts a central bright band followed by a series of maximas and minimas on either side *the equation for a single slit diffraction is diff than the equation for a double slit, instead it is: asinθ=mƛ, where a is the width of the slit. Now, this equation will give you the destructive interference points. Not the constructive interference points. *maxima occurs for m= 0 (big central maxima), +/-1.5, +/-2.5, etc *minimum occurs for m= +/-1, +/-2, +/-3, etc (light/electromagnetic radiation)

Polarized light:

light w electric field oscillating in only one plane. To get light to become polarized, you can: 1)selective absorption: pass light through a polarizer that absorbs all but light w electric field in one plane 2)reflection: at a certain polarizing angle, all reflected light is polarized. *the extent to which polarization occurs is dependent upon the angle at which the light approaches the surface and upon the material that the surface is made of. Metallic surfaces reflect light with a variety of vibrational directions; such reflected light is unpolarized. However, nonmetallic surfaces such as asphalt roadways, snowfields and water reflect light such that there is a large concentration of vibrations in a plane parallel to the reflecting surface. A person viewing objects by means of light reflected off of nonmetallic surfaces will often perceive a glare if the extent of polarization is large. Fishermen are familiar with this glare since it prevents them from seeing fish that lie below the water. Light reflected off a lake is partially polarized in a direction parallel to the water's surface. Fishermen know that the use of glare-reducing sunglasses with the proper polarization axis allows for the blocking of this partially polarized light. 3)double refraction: birefringent materials have two indexes of refraction that splits the incident light into two rays polarized perpendicular to each other *refraction occurs when a beam of light passes from one material into another material. At the surface of the two materials, the path of the beam changes its direction. The refracted beam acquires some degree of polarization. Most often, the polarization occurs in a plane perpendicular to the surface. In double-refracting birefringent materials, like crystal calcite, incident light is refracted into two different paths. The light is split into two beams upon entering the crystal. Subsequently, if an object is viewed by looking through the crystal, two images will be seen. The two images are the result of the double refraction of light. Both refracted light beams are polarized- one in a direction parallel to the surface and the other in a direction perpendicular to the surface. 4)scattering: air molecules scatter light, which becomes polarized *polarization also occurs when light is scattered while traveling through a medium. When light strikes the atoms of a material, it will often set the electrons of those atoms into vibration. The vibrating electrons then produce their own electromagnetic wave that is radiated outward in all directions. This newly generated wave strikes neighboring atoms, forcing their electrons into vibrations at the same original frequency. These vibrating electrons produce another electromagnetic wave that is once more radiated outward in all directions. This absorption and reemission of light waves causes the light to be scattered about the medium. (This process of scattering contributes to the blueness of our skies) (geometrical optics)

Optics that must be known for the mcat:

mnemonic to remember: 1) "I would DIE hiding in a CAVE with bears." ConCAVE lens are DIverging 2) concave lens and convex mirrors are the same 3) Hunters would go after the bear if it killed me and skin its hide to make leather interior for a new SUV; the Diverging SUV! All diverging systems create images that are small, upright, and virtual (SUV). 4) has a -f, can create virtual erect images 5) so, concave mirrors and convex lens are converging. They have a +f and can create real inverted and virtual erect images Tend: real inverted and small; getting bigger along the way until it becomes virtual erect. 6) lens equation, 1/o + 1/i = 1/f i is positive, real image i is negative, virtual image 7)magnification equation, m=-i/o m is positive, erect image m is negative, inverted image *real image=inverted *virtual image=erect 7) nearsightedness → MYopia if affects me, it is MY problem eyeball is too long. Light converges too early. Need a diverging lens to stretch light MYopia, Diverging lens, Concave lens 8)farsightedness → Hyperopia; Presbyopia (aging) eyeball is too short. Light is hitting beyond back of eye. Light must be converged (shortened) to it reaches back of retina Hyperopia, Converging lens, Convex lens

The doppler effect:

occurs when the source of a sound wave is moving relative to the detector. The result is that the perceived or detected frequency (the pitch) will be different from the frequency of the sound that was emitted from the source. Two key points: -if the source and detector are moving closer together, the detected frequency will be higher -if the source and detector are moving farther apart, the detected frequency will be lower Variations of the wave equation, v=ƛf: 1) IF A DETECTOR MOVES toward or away from a stationary source, then the wavelength is constant. Only the velocity and frequency of a wave is changing to the observer, v=ƛf. *for ex, if a sound wave is moving towards the detector at 340m/s and the detector moves toward the source at 20m/s, the wave will appear to be moving at 360m/s in the detector's frame of reference. If the perceived wave velocity is increasing, then the perceived frequency is increasing. The wavelength will not change. 2) IF THE SOURCE MOVES toward or away from a stationary detector, then the velocity is constant. Only the wavelength and frequency is changing to the observer, v=ƛf. *for ex, when the source moves, the waves become distorted, thus wavelength is changed. If wavelength increases, frequency decreases. If wavelength decreases, frequency increases. -To predict what the perceived frequency will be, use the equation in the pic (fo is observed frequency. fs is actual frequency emitted by the source. v is the speed of sound. vo is the speed at which the observer is travelling. vs is the speed at which the source is travelling). In equation, use the top signs when the motion is toward. Use the bottom sign when motion is away. Note: speed of sound in air, v=350 m/s -if the velocities are constant, then the observed frequency is constant (sound)

Colloid:

particles 2-500nm. Things are mixed at a "semi-molecular level." Particles are small enough where they will stay suspended. Will only come unsuspended if you centrifuge it. For ex, jello (gelatin powder stays suspended in water), or fog (liquid water molecules inside an air mixture), or smoke (solid smoke particles inside an air mixture), or homogenized milk (milk you buy at the store has fat particles which stay suspended in the milk)

Speed:

rate of change in distance; scalar, no direction. Can be described by: Average speed = distance/Δt -instantaneous speed= speed at an instant (infinitesimal time interval) -instantaneous speed equals instantaneous velocity in magnitude -you cannot have a negative speed (think of speedometer in your car, only tells you + values) -units are in m/s Ex, a sprinter runs around a circular track of radius 100m. This takes 2min for her to complete one lap. What is the runner's average speed? Avg speed=distance/Δt → speed=pi(200m)/120s → 5m/s is her speed *note: we used the circumference of a circle to get distance (translational motion)

What does it mean for resistors to be in series? What is true about the voltage drops across such resistors? The currents?

series= one resistor after another along the path of the current. Series resistors share the same I. V's may be different and must add up to the total V supplied by the power source

Solute vs solvent:

solute is the species present in the smaller quantity. The solvent is the species present in the larger quantity. *weird exception: EtOH, (rubbing alcohol), here the solute (ethanol) is present at 95% while the solvent (water) is present at only 5% (gas phase)

Solubility:

the amount of a substance that can dissolve in a specific solvent at a given temperature. Solubility is usually written in mass/volume. For ex, the solubility of NaCl is 10g/100mL. So, for every 100mL of water you have, 10g of NaCl will dissolve in it. Everything has a certain solubility associated w it. Solubility rules: 1)with SOLID and LIQUID solutes in water: -solubility is directly proportional to T *increase the temp, increase the solubility -solubility is not affected by pressure *summary: solubility∝T 2)with GASEOUS solutes in water: -solubility is indirectly proportional to T -solubility is directly proportional to pressure *summary: solubility∝P∝1/T Ex= pop in a cup in the fridge, this is necessary to keep the CO2 in the pop. If you allowed the pop to sit outside on a hot deck in a cup, the pop would quickly go flat (all CO2 would leave the liquid). *When temp rises, the gas wants to leave the solution. *if you want to get CO2 into the pop, you can cool the temp or increase the pressure (gas phase)

Volume:

the amount of space that a substance or object occupies. The SI unit for volume is the cubic meter (m³), but in chemistry, the cubic centimeter (cm³ or cc) and liter (L) are commonly used. 1cm³ = 1cc = 1mL and 1m³ = 1000L And, 1000mL = 1L (gas phase)

The anode is always the site of _____. While the cathode is always the site of ______.

the anode is always the site of oxidation. While the cathode is always the site of reduction (galvanic cell) (electrochemistry)

Refraction:

the bending of a wave when it meets a boundary between one medium to another. *the angle of refraction is the angle that the transmitted (or refracted) ray makes w the normal. It will vary based on the index of refraction for a medium, n. *to find the angle of refraction, use Snell's Law (geometrical optics)

Pressure (fluids):

the force exerted over an area, P=F/A. -The SI unit for pressure is the pascal, Pa, where 1Pa = 1N/m^2. -The pascal is inconveniently small for most calculations, so several alternatives are used. Primarily pressure is expressed in kPa. -if an object is placed in a fluid, the fluid will exert a force on the object. *remember, 1 atm = 760 torr = 760 mmHg = 101 kPa = 101,000 Pa (fluids)

Pressure (gases):

the force exerted over an area, P=F/A. The SI unit for pressure is the pascal, Pa, where 1Pa = 1N/m². This unit is inconveniently small for most calculations involving gases, so several alternatives are used. -at sea-level, atmospheric pressure is about 101,000 pascals (or 101 kPa). This is 1 atmosphere (1atm). -related to the atmosphere is the torr, where 1atm = 760 torr *note: 1 torr is approximately how much pressure is exerted by a nickel sitting on a table -at 0C, 1 torr is equal to 1 mmHg (millimeter of mercury) 1 atm = 760 torr = 760 mmHg = 101 kPa = 101,000 Pa -when performing P=F/A calculations, make sure F is in Newtons, A is in meter squared, and the resulting P will be in Pascals. You can then convert the Pascals to whatever units the answer choices are in (gas phase)

Conduction electrons:

the free electrons in a conductor that are capable of moving. *drift velocity, (vd), occurs when conduction electrons in a conductor move one way or the other *current occurs when there is a net movement of conduction electrons (there is a net movement of charge) **If a conductor has a drift velocity in a certain direction, then their is a flow of charge, a current (Circuit Elements)

Sound attenuation:

the gradual loss of intensity as sound travels through a medium. Sound attenuation is greatest for soft, elastic, viscous, less dense material. Attenuation is a measure of the energy loss of sound propagation in media. Most media have viscosity, and are therefore not ideal media. When sound propagates in such media, there is always thermal consumption of energy. *media/objects that absorb sound= soft (not hard); elastic (not rigid); viscous (not watery); less dense objects (sound)

In the visible spectrum, blue light has:

the greatest energy, shortest wavelength, highest frequency (geometrical optics)

In the visible spectrum, red light has:

the least energy, longest wavelength, lowest frequency (geometrical optics)

Threshold of hearing:

the lowest intensity the human ear can perceive as sound. *the threshold of hearing for humans is I₀ = 1x10⁻¹² W/m² (sound)

Absolute zero:

the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. It occurs at: K= 0 C= -273 F= -460 (gas phase)

Archimedes' principle:

the magnitude of the buoyant force is equal to the weight of the fluid displaced by the object. Fbuoyancy= (⍴fluid)(Vsubmerged)(g) (fluids)

Torque:

the measure of a force's effectiveness at making an object spin or rotate (in other words, it's the measure of a force's effectiveness at making an object accelerate rotationally). If an object is initially at rest, and then it starts to spin, something must have exerted a torque. -torque is the angular equivalent of force; it makes things rotate, have angular acceleration, change angular velocity and direction. -the center of turning= pivot point or fulcrum -the vector from the pivot point to the point of application of force= radius vector or lever arm -the angle between vectors r and F is theta -Torque is expressed as: 𝛕=rFy or 𝛕= rFsinθ, with units of Nᐧm -CCW rotation torques are positive -CW rotation torques are negative *since it has direction, torque is a vector -if a force is applied at a 0° or 180° angle to the radius vector, then the torque is zero. We can see this by sin(0)=0 and sin(180)=0 *additionally, if a force is applied at the fulcrum, then its torque is zero -maximum torque occurs when a force is applied at a 90° angle to the radius vector. If the force is perpendicular to the radius vector, then 𝛕=rF. We see this bc sin(90)=1. -if you apply a force at a long distance from the fulcrum, you exert a greater force on a position closer to the fulcrum, (you exert a greater torque). The catch is that you need to move the lever arm through a longer distance. For ex, when opening a door, you push on the outer edge of the door, away from the fulcrum, (large radius), at a 90 degree angle. You apply little force, and get a large torque. While the lever arm (the door) swings open. Imagine if you pushed on the door, at a 90 degree angle, but this time you push right next to the fulcrum. Since radius is very tiny, you would have to apply a huge force to get the same torque. *another way to say this, as radius from the pivot point increases, torque also increases (Equilibrium)

Phase diagrams:

the phase of a substance doesn't depend just on the temp, it also depends on the pressure. For ex, even at high temps, a substance can be squeezed into the liquid phase if the pressure is high enough. And at low temps, a substance can enter the gas phase if the pressure is low enough. A substance's phase diagram shows how its phases are determined by temp and pressure Three phases: solid, liquid gas: -Solid: high pressure, low temp -Liquid: intermediate pressure, intermediate temp -Gas: low pressure, high temp Imp lines on the phase diagram: -solid-liquid boundary= line on graph where solids and liquids exist in equilibrium (like a glass of ice water). Has a positive slope. The fp/mp temp increase when you increase the pressure *density of solid > density of liquid -solid-gas boundary= line on graph where solids and gases exist in equilibrium. Has a positive slope. Occurs at low temp and low pressure. *density of solid > density of gas -liquid-gas boundary= line on graph where liquids and gases exist in equilibrium (like boiling water). Has a positive slope. The bp/condensation temp increase when you increase the pressure *density liquid > density of gas Imp points on the phase diagram: -triple point= the temp and pressure at which all three phases of matter coexist in equil. Equal amount of solid/liquid/gas -critical point= the temp and pressure at which liquids and gases become indistinguishable. When you cannot tell liquid/gas particles apart, this is called a supercritical fluid. No amount of increased pressure can force the substance back into its liquid phase -critical temperature= the temp above which you can no longer get a liquid, no matter how much pressure you press on it. Vapor of the substance cannot be liquefied, no matter how much pressure is applied. *note: all the above info is for most phase diagrams. The water phase diagram is different.

Acceleration:

the rate of change in velocity. Acceleration changes if an object's velocity changes (speeding up or slowing down), or if it's direction changes. Acceleration is a vector. Can be described by: average acceleration = Δv/Δt. Note: average acceleration is written w a bar over "a" -you can have a positive or negative acceleration -units are in m/s^2 -uniformly accelerated motion = motion along a straight line (no change in acceleration; not speeding up or slowing down. No change in direction) -the direction of acceleration tells how the velocity will change: *if the acceleration points in the same direction as velocity, an object's speed is increasing (ex, stepping on the gas pedal, speeding up) *If the acceleration points in the opposite direction as velocity, an object's speed is decreasing (ex, stepping on the brake, slowing down) *if acceleration points perpendicular to velocity, an object's speed is constant (ex, going around a curve at a constant speed, acceleration is either increasing or decreasing) *if acceleration points at an angle between 0 and 90 degrees to velocity, an object's speed is increasing and direction of velocity is changing *if acceleration points at an angle between 90 and 180 degrees to velocity, an object's speed is decreasing and direction of velocity is changing Ex, a sprinter runs around a circular track of radius 100m. This takes 2min for her to complete one lap. If the runner runs at a constant speed, what is the magnitude of her avg acceleration? Avg velocity=displacement/Δt. Since the runner is running in a circle, her displacement is 0. Therefore, avg velocity=0, and avg acceleration=0/Δt → 0 is her avg acceleration *Note: her instantaneous acceleration is not zero. At each instant in time, her direction is changing. Instantaneous or centripetal acceleration is the motion towards the center of a circle (translational motion)

Graham's Law of effusion:

the rate of diffusion or effusion of a gas is inversely related to the square root of its molar mass. Expressed by: rate of gas 1/rate of gas 2 = √ molar mass of gas 2/molar mass of gas 1 -heavy particles move slowly -light particles move quickly -temperature vs KE vs speed of the gas: the molecules of two different gases at the same temperature have the same average KE. But the molecules of two different gases at the same temperature don't have the same average speed. Lighter molecules travel faster, bc KE depends on both the mass and the speed of the molecules. -Graham's Law is derived from the kinetic molecular theory *temperature is proportional to average KE *at a given temperature all gases have the same KE -sometimes with Graham's Law problems, the speed of the molecules, v, will be given to you in rms, (root-mean-square), which is just the square root of the mean (average) of the square of speed. **see pic

Electrostatics:

the study of stationary electric charges or fields as opposed to electric currents. (Electrostatics)

Electric fields:

the very existence of a charge alters the space around it, creating an electric field, E. If a second charge happens to be there or to roam by, it will feel the effect of this field created by the original charge. This is the electric force on a second charge, (q), denoted by the field *Source charge= charge creating the electric field, can be + or -. Denoted as Q *Test charge= + charge entity placed in the field By convention then: -if source charge is +, it will repel the + test charge -if source charge is -, it will attract the + test charge Thus: electric field vectors, E, always point away from positive source charges. electric field vectors, E, always point toward negative source charges *electric fields come out of positive charges, and goes into negative charges *the unit for electric field is N/C, or newtons per coulomb *lines that are closer together denote stronger fields than lines that are farther apart Equations: 1) to determine the electric field, E, created by the source charge, Q, use the formula: E= k Q/r². Where r represents the distance from Q to some point in space where we want to know the electric field vector 2) to determine the force that a second charge, q, feels while in an electric field, use the formula: Felectricalonq=qE *Felectricalonq is in the same direction as E for positive charges *Felectricalonq is in the opposite direction as E for negative charges (Electrostatics)

Work done by an electric field:

to find the work done by the electric field as a charge moves, use: Wbyelectricfield = -ΔPEelectric *remember, the change in gravitational PE is equal to the opposite of the work done by the gravitational field. That is, ΔPEgravitatinoal = -Wbygravity. This same concept is used here! So, work by the electric field and electric PE always have opposite signs *a negative ΔPE is spontaneous, (moving w nature). A negative ΔPE means positive work was done by the field (electric force is in the same direction as displacement). And ΔKE is increasing. *a negative ΔPE is nonspontaneous, (moving against nature). A negative ΔPE means negative work was done (electric force is in opposite direction as displacement). And ΔKE is decreasing. (Electrostatics)

Isoelectric:

two elements that have the same electron configuration/same number of valence electrons. For ex, F- and Ne (atomic nucleus)

Lead-acid batteries:

type of rechargeable battery; this is your car battery. Lead-acid batteries are a type of galvanic cell that uses two different oxidation states of Pb for its electrodes and sulfuric acid as an electrolyte. Fully charged lead-storage batteries use Pb as an anodic electrode and PbO₂ as a cathode. As the battery discharges, Pb undergoes a two electron oxidation to PbSO₄, and PbO₂ is reduced to PbSO₄ *recharging the battery involves applying a voltage to reverse the electron flow (electrochemistry)

A gas is no longer considered to be an ideal gas when it's at ______.

very high pressure, low temperature. At these conditions, the gas molecules are "squished" together. When the gas molecules are squished together, they experience intermolecular interactions. Also, the molecular volume become significant when the total volume is squished down so much. The intermolecular attractions will cause collisions to be sticky and inelastic. At the extremely high pressure and low temps, gases cease to be gases at all; they condense into liquids (gas phase)

An object has an initial velocity of 3m/s and a constant acceleration of 2m/s^2 in the same direction. What will the object's velocity be at t=6s?

vf= v₀ + at → vf= 3m/s + (2m/s²)(6s) → 15m/s (translational motion)

An object starts from rest and travels in a straight line w a constant acceleration of 4m/s² in the same direction until its final velocity is 20m/s. How far does it travel during this time?

vf²=v₀² + 2ad → d=v²/2a → d= (20m/s)² // (2)(4m/s²) → 50m (translational motion)

Flow rate:

volume of fluid that passes a particular point per unit time. Expressed by: f=Av, where A is the cross-sectional area, and v is the average speed of the flow -flow rate has units of m³/s -be careful not to confuse flow rate w flow speed. Flow rate tells us how much fluid flows per unit time. Flow speed tells us how fast the fluid moves. There's a difference between saying that a hose that ejects 4L of water every second (that's flow rate) and saying that the water leaves the hose at a speed of 4m/s (that's flow speed) *hydrodynamics (fluids)

What happens in the d subshell when writing electron configurations?

watch out for the d⁴ and d⁹ elements. Instead of s²d⁴ and s²d⁹, its s¹d⁵ and s¹d¹⁰. A half-filled or fully filled d subshell is very stable **e- are always removed from the 4s subshell before the 3d subshell (electronic structure)

Transverse waves:

wave displacement is perpendicular to the direction of motion. -includes: visible LIGHT, and other forms of electromagnetic radiation. -ex, you hold a slinky on the left end and move it up and down. Energy will be transported through the slinky from left to right. The individual coils of the slinky will move up and down in a wave motion. Wave displacement (up and down) is perpendicular to the direction of motion (left to right) (periodic motion)

Define weight. Give at least two reasons why mass is different from weight

weight is the gravitational force acting on an object. It varies w location and is measured in newtons. Mass is not a force and does not vary w location (ex on earth vs on the moon). It is measured in kg.

Photon energy:

when EM radiation interacts w matter (absorption and emission), we find that it carries energy, and that the energy is quantized. That is, the energy associated w EM radiation is absorbed or emitted by matter in "packets." Each bundle of energy is called a photon. The energy of a photon is directly proportional to the frequency: E=hf=hc/ƛ, where h is Planck's constant (6.63x10⁻³⁴ Jᐧs) and c is speed of light (3x10⁸m/s) energy∝frequency, if you increase energy, frequency increases energy∝1/wavelength, larger wavelength means a small energy frequency∝1/wavelength, large wavelength means a slow frequency (geometrical optics)

Total internal reflection:

when a light ray traveling in a medium of high refractive index approaches a medium of lower refractive index (for ex, light traveling from water to air), total internal reflection occurs if the angle of incidence > the critical angle. *total internal reflection= all of the incident ray's energy will be reflected back into its original medium. There will be no refracted ray. *to find the critical angle for total internal reflection, use: sin(θcriticalangle)= n₂/n₁, where n₁ is the refractive index of the medium through which the incident ray is traveling, and n₂ is the refractive index of the medium on the other side of the boundary Summary: -if θ₁ > θcriticalangle, then total internal reflection will occur -if θ₁ < θcriticalangle, then total internal reflection will NOT occur. You will have a refracted ray -if θ₁ = θcriticalangle, then the refracted ray skims along the boundary, with θ₂=90° -total internal reflection can only occur if n₁ > n₂ (for ex, light traveling from a more dense material to a less dense material, like water to air) (geometrical optics)

Standing sound waves in a closed pipe:

when a pipe is closed on one end: -there is an antinode at the open end and a node at the closed end *antinodes are also called pressure nodes; areas of constant pressure *nodes are also called pressure antinodes; areas of max pressure -the distance between the antinode and node is equal to an odd number of quarter wavelengths. Given by: 𝝺= 4L/n and 𝝺=𝝺fundamental/n f= nv/4L and f=(n)(ffundamental) *where the harmonic number, n, must be an odd number, and v refers to the speed of sound in air. *n must be an odd number! Thus, you can only plug in 1, 3, 5, 7, etc. (sound)

Collisions:

when analyzing collisions between objects, total momentum is always conserved. ptotalbefore = ptotalafter m₁v₁ + m₂v₂ = m₁v'₁ +m₂v'₂ Collisions are grouped into two major types: 1) elastic collisions= total momentum and total KE are conserved 2) inelastic collisions= total momentum is conserved but total KE is not *a subcategory of inelastic collisions is perfectly (or completely) inelastic collisions. This is where the objects stick together after the collision (Equilibrium)

Power in circuits:

when current passes through a resistor, the resistor gets hot, (it dissipates heat). The rate at which it dissipates heat energy is the power dissipated by the resistor. The formula used to calculate power is known as the "Joule Heating Law," expressed by: P=I²R, where P is power, I is current, and R is resistance *the Joule Heating Law can also be written as: R=I/V and P=I²R, so we can get P=IV *power has units of Watts, W *total power supplied by a battery equals the total power dissipated by the resistors *power companies try to save the amount of copper needed for power lines by using thinner wires, which makes R quite high *to minimize P dissipated by the wires, they minimize I by maximizing V. This is why power lines transfer electricity at high voltage. *on the mcat, along w questions about power, there could also be questions about energy. Remember, power=energy/time (Circuit Elements)

Thin-film interference:

when it rains outside, puddles form. Sometimes, oil left over on the roads falls into water puddles, creating a thin film of oil on top of water. This can be seen as a swirly rainbow. You can also see a swirly rainbow when you look into a bubble. *this is thin-film interference. Light rays from the sun strike the oil-puddle. Some light rays traveling perpendicular to the oil-puddle surface will be reflected back onto itself, and some will undergo refraction, passing from the air into the oil. When the refracted ray hits the next interface, going from oil to water, some rays will be reflected, and some will undergo refraction. *the waves which were reflected can undergo interference, which your eyes can see. Some waves may be constructive and some waves may be destructive. You will see diff colors based on diff wavelengths of light (remember, you were starting with white light, which is all colors of the visible spectrum) *for thin-film interference to occur, you have to have a thin film which light can pass through, like oil Summary: light reflecting off the outer and inner boundary of a thin film interfere with each other (light/electromagnetic radiation)

Specific heat of transition:

when matter undergoes a PHASE TRANSITION, energy is either absorbed or released. The amount of energy required to complete a transition is called the "heat of transition," ΔH. For ex, the amount of heat that must be absorbed to change a solid into a liquid is called the "heat of fusion," and the energy absorbed when a liquid changes to a gas is the "heat of vaporization." Each substance has a specific heat of transition for each phase change. *The specific heat of transition, (how much heat is required to cause a phase change), is dependent on the substance, (intermolecular interactions), and the amount of the substance (in moles). For ex, heat of fusion for water is 6 kJ/mol. So, if you wanted to melt a 2mol sample of ice (at 0C), 12 kJ of heat would need to be supplied. Similarly, if that 2mol sample was converted from a liquid to a solid, 12kJ of heat would be released The amount of heat, q, accompanying a phase transition is given by: q = (n)(ΔHphase change), where n is the # of moles, and ΔH is the molar enthalpy of phase change (given in kJ/mol) *if ΔH and q are positive, heat is absorbed. *if ΔH and q are negative, heat is released (phase transition diagram/heating curve) (gas phase)

Dielectric breakdown:

when the electric field strength between the plates of a capacitor becomes so strong that the dielectric becomes ionized, providing a route for electrons on the negative plate to return to the positive plate, we say that the dielectric has suffered dielectric breakdown. This is what essentially causes lightning. *the bottom region of a thundercloud is negatively charged and the surface of the earth below the cloud is positively charged; these surfaces act as oppositely charged plates in a huge parallel-plate capacitor. When the voltage, V, becomes so great that E=V/d exceeds 3 million volts per meter, the air is ionized, and charge is transferred in a spectacular bolt of lightning. (Circuit Elements)

Rotational equilibrium:

when things are at rotational equilibrium, the sum of all torques = 0. -remember, positive torques act counter-clockwise and negative torques act clockwise. -when things are at rotational equilibrium, they either don't rotate or they rotate at a constant rate (angular velocity, ⍵, or frequency, f, are constant) -you cannot have rotational equilibrium if there is angular acceleration, α, (if there is a change in angular velocity, ⍵, this means angular acceleration is no longer constant) Things at rotational equilibrium: -equal weights on a balance -propeller spinning at a fixed frequency -asteroid rotating at a constant pace as it drifts in space Things NOT at rotational equilibrium: -unequal weights in a balance, such that the balance begins to tilt -propeller spinning faster and faster -propeller slowing down (Equilibrium)

Translational equilibrium:

when things are at translational equilibrium, the vector sum of all forces = 0. Things at translational equilibrium either don't move, or are moving at a constant velocity. This means the acceleration = 0. -if an object is accelerating, it's not in equilibrium -if an object is decelerating, it's not in equilibrium. *deceleration is just acceleration in the opposite direction Things at translational equilibrium: -an apple sitting still -a car moving at constant velocity -a skydiver falling at terminal velocity Things NOT at translational equilibrium: -an apple falling toward earth w an acceleration of g -a car either accelerating or decelerating -a skydiver before he reaches terminal velocity (Equilibrium)

Friction:

when two surfaces are in contact, there's an electrical attraction between the atoms of one surface w those of the other. This attraction will make it difficult to slide one object relative to the other. -like any other force, friction is a vector. It is always oriented in the direction opposite to the motion -static friction pertains to objects sitting still. Use static friction when an object is not "sliding" on a surface, or when something is "rolling w/out slipping" (like a car tire when driving. Only one part of the wheel is in contact w the ground at a given time, this point experiences Fg, Fn, and Ffs). An object can sit still on an inclined plane bc of static friction. It is given by: Ffs = µsFn, where µ is the coefficient of static friction. -kinetic friction pertains to objects in motion. A book sliding or slipping across the table eventually comes to a stop bc of kinetic friction. It is given by: Ffk = µkFn, where µ is the coefficient of kinetic friction. -the coefficient of friction is intrinsic to the material properties of the surface and the object, and is determined empirically -the coefficient of static friction is always larger than the coefficient of kinetic friction -static friction is always larger than kinetic friction -the normal force at a horizontal surface is equal to the weight (if you are not applying an additional force to the object; you are not pushing down on it, etc) -the normal force at an inclined plane is equal to the weight times the cosine of the incline angle -lubricants reduce friction bc they change surface properties -we can walk and cars can drive bc of friction -everytime there is friction, heat is produced as a by-product (Force)

Free fall:

whenever something is tossed in the air, it's in freefall -motion taking place under constant acceleration, ay = g = 10m/s² -since acceleration is constant, use the Big Five kinematic equations! -the acceleration due to gravity is constant bc the force (weight) and mass of the object is constant -if the object's initial displacement is up, use -10m/s² for gravity -if the object's initial displacement is down, use 10m/s² for gravity -the net acceleration is a constant, g, if you don't take air resistance into consideration. Usually questions ignore air resistance. But if the question gives you air resistance, then the acceleration is no longer constant. The acceleration will decrease w time until it gets to zero at terminal velocity. Terminal velocity = the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration. *when there's air resistance, the acceleration will decrease bc the force (Fweight - Fresistance) is decreasing due to increasing resistance or friction at higher speeds. At terminal velocity, the weight=air resistance, so the net force is 0. Thus the acceleration is 0. So, the speed stays constant at terminal velocity. (translational motion)

Some common reduction potentials:

you will find reduction potentials in a table. *However, some good ones to remember are: 1) Chlorine has a high electron affinity, it loves to gain electrons and get reduced. Thus, it has a positive/high reduction potential (E= 1.4V) Cl2 + 2e- → 2Cl- -Similarly, species like oxygen, halogens, and nonreactive metals have positive reduction potentials (want to gain electrons) *note: nonreactive metals (also called noble metals) do not easily undergo chemical reactions. They include, ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au). 2) Sodium hates its electron, it gets rid of it to obtain a full outer shell. It is stable as a cation. It is very hard to force electrons onto a stable cation to reduce it. Thus, it has a very negative reduction potential (E= -2.7V) Na+ + e- → Na -Similarly, species like potassium and other reactive metals have negative reduction potentials. (electrochemistry)

State the sign of ∆H and ∆S for each of the six phase changes, and rank them from highest magnitude to lowest

∆Hsub > ∆Hvap > ∆Hfus >0. The other three ∆H values are negative, with |∆Hdep| > |∆Hcond| > |∆Hfreez|. *Note that ∆Hsub=|∆Hdep|, ∆Hvap=|∆Hcond|, ∆Hfus=|∆Hfreez|. ∆Ssub > ∆Svap > ∆Sfus >0. The other three ∆S values are negative, with |∆Sdep| > |∆Scond| > |∆Sfreez| *Note that ∆Ssub=|∆Sdep|, ∆Svap=|∆Scond|, ∆Sfus=|∆Sfreez|

Give the formulas for the change in the electrical potential energy of a charge q and the work done on the charge in terms of the voltage between its starting and ending locations

∆PEelectric=qV Work done by electric field = -∆PE = -qV

What is the density of liquid water?

𝝆 = 1g/mL = 1g/cm^3 = 1kg/L = 1000 kg/m^3 (fluids)

An organ pipe that is open at both ends has a length of 3m. What is the second longest harmonic wavelength for sound waves in this pipe?

𝝺= 2L/n → 𝝺= 2(3)/n *the longest harmonic wavelength is: 𝝺= 2(3)/1 → 6m *the second longest harmonic wavelength is: 𝝺= 2(3)/2 → 3m Answer is 3m (sound)

An organ pipe that is closed at one end has a length of 3m. What is the second longest harmonic wavelength for sound waves in this pipe?

𝝺= 4L/n → 𝝺= 4(3)/n *the longest harmonic wavelength is: 𝝺= 4(3)/1 → 12m *the second longest harmonic wavelength is: 𝝺= 4(3)/3 → 4m Answer is 4m (sound)

What are the official names for the six phase changes?

fusion (melting), freezing, vaporization, condensation, sublimation, and deposition

Deposition:

going from a gas → solid

Pitch:

the human perception of the frequency of sound. Higher frequency = higher pitch (squeaky girly voice vs low-deep voice) (sound)

Use long division to solve 250 ÷ 6

41.6

Define capacitor, capacitance, and dielectric. In what units is capacitance measured?

Capacitor: two conductors (usually parallel plates) carrying equal but opposite charges. Capacitance=charge/voltage , C=Q/V, with units of farad, where 1F=1C/V Dielectric: insulator between capacitor plates

For people with hyperopia or presbyopia, what correcting lens do they need?

For farsighted pt's, they need a converging/convex lens; light needs to be shortened to reach back of retina Eyeball is too short! (geometrical optics)

Which ions always result in a soluble salt? Which ions generally form insoluble salts?

Group 1, ammonium, nitrate, acetate, and bicarbonate salts are always soluble in water. Pb, Ag, and Hg salts are generally insoluble in water, unless paired with the anions previously mentioned

Give an example of a gas that most closely approaches ideal behavior

Helium

Units of temperature:

Kelvin, K

Define momentum. Is it a vector or is it a scalar? Define impulse. It is a vector or is it scalar?

Linear momentum, p=mv Impulse, J=F∆t Both p and J are vectors

element Mn

Manganese

Fusion:

Melting. Going from a solid → liquid

Units of volume:

Meter cubed, m³

Atomic number:

Number of p+'s Written form: Z is the number of protons in the nucleus of an atom. This determines what element the atom is. Shown explicitly by a subscript before the symbol of an element, for ex, ₄Be Periodic table: number on top of atom symbol **the atomic number tells you # of protons, nuclear charge, and determines the element Way to remember: atomic number is FUNDAMENTAL to what atom it is, so it's at the FOUNDATION (shown in a tiny subscript at bottom) (atomic nucleus)

Units of resistance:

Ohm, Ω

One mole contains ______ molecules.

One mole contains 6.02x10²³ molecules (gas phase)

Give the formulas for the power lost by a resistor and for the power supplied by a voltage source

Power lost by a resistor: P=I²R=IV=V²/R. Power supplied by voltage source: P=IV

Define power. In what units is it measured? Is it a vector or is it a scalar?

Power=work/time=energy/time. It is a scalar, measured in watts, W, where 1W=1J/sec

What determines wave speed?

Properties of the medium (except when taking into account dispersion w light, where frequency also matters to a small extent)

NMR:

Proton Nuclear Magnetic Resonance, (^1H NMR or NMR), is a type of absorption spectroscopy used to identity an unknown compound by using resonant properties -the nucleus of a hydrogen atom is a proton. Protons have spin (+½ and -½, counterclockwise or clockwise). And, any moving electric charge creates a magnetic field. So, protons can be thought of as tiny magnets -protons in an applied external magnetic field, B, can either be aligned with the magnetic field (spin aligned, called 𝛂 spin state) or aligned opposite the magnetic field (not-spin aligned, called 𝜷 spin state). Their is a difference in energy, ΔE, between the 𝛂 and 𝜷 spin state, with the 𝜷 spin state being higher in energy. If you applied a larger external magnetic field, you will increase the energy difference between 𝛂 and 𝜷 spin states to a greater extent. If a proton absorbs the correct amount of energy, it can flip from 𝛂 to the 𝜷 spin state. When this happens, the nucleus is said to be "in resonance with your applied magnetic field". The energy difference between your two spin states, ΔE, corresponds to a frequency (remember, E=hf, where E is energy, h is planck's constant, and f is frequency in hertz). This frequency falls in the radio wave region of the EM spectrum. So, with NMR: -take a sample of your compound. Nuclei in your sample will either be in 𝛂 or 𝜷 spin state. There will be slightly more in 𝛂 spin state, bc it is lower in energy. -put sample in NMR spectrometer, which has an external magnetic field. -hit sample with a short pulse that contains light from the radio frequency of the EM spectrum. Some 𝛂 will change to 𝜷 spin state. When nuclei go back to 𝛂 spin state, the NMR machine detects the energy that's given off. This is detected as a signal on an NMR spectrum. -the NMR spectrum graphs frequency (corresponding to a certain wavelength) vs intensity (corresponding to the number of absorptions at a particular wavelength). It's possible to get diff signals (diff peaks on your graph) at diff frequencies. Different frequencies just means differences in energy, ΔE, required to go from 𝛂 to 𝜷 spin states; different amounts of energy given off during emission. -shielding: electrons move around the nucleus. If electrons are moving around the nucleus in the opposite direction as the applied magnetic field, B, then the proton will feel an overall smaller magnetic field bc electrons shield it. So, if you increase electron density around proton, you increase the shielding. This causes a decreased magnetic field (due to electrons opposing magnetic field), and a decrease in energy, ΔE, that is needed to go from 𝛂 to 𝜷 spin state. A proton in a molecule (a hydrogen atom) is shielded bc there is electron density around it. *shielded protons absorb lower frequency radio waves (need less energy to move from 𝛂 to 𝜷 spin state; lower ΔE). They are graphed upfield (need a higher applied magnetic field strength to move from 𝛂 to 𝜷) *deshielded protons absorb higher frequency radio waves (need more energy to move from 𝛂 to 𝜷 spin state, higher ΔE). They are graphed downfield (need a lower applied magnetic field strength to move from 𝛂 to 𝜷) Features of a molecule you can get from its NMR spectrum: 1) Equivalent hydrogens: Is there multiple peaks on the graph? -equivalent hydrogens in a molecule are those that have identical electronic environments. Such hydrogens have identical locations in the NMR spectrum, and are represented by the same signal or resonance. For ex, C2H6 will give you 1 NMR signal, bc all six hydrogens are equivalent -nonequivalent hydrogens will have different locations in the NMR spectrum and are represented by different signals (multiple peaks). For ex, C3H8 will give you 2 NMR signals bc there are two diff nonequivalent hydrogens -What makes protons "different" is the degree of electron shielding or deshielding. *Next to stuff like carbon, hydrogen is shielded by electrons because carbon is not so electronegative. *Next to stuff like oxygen, hydrogen is deshielded because oxygen is very electronegative. *When things are shielded, the magnetic field is smaller and they have small chemical shifts and appear upfield (to the right). *When things are deshielded, the magnetic field is larger and they have large chemical shifts and appear downfield (to the left). 2) Chemical shift: Where are the peaks located, upfield or downfield? -If we were to give the protons some energy (by radio wave absorption), then the protons can be promoted (flipped) to the higher energy spin, which is opposite to the direction of the external magnetic field. This absorption is called resonance. The resonance frequency is the frequency of the radio wave that's needed to cause a flip in spin. The resonance frequency (or energy or field strength) of absorption is called the chemical shift. *Different protons have different resonance frequencies. *Equivalent protons have the same resonance frequencies. *You can substitute X at any of the equivalent protons, and you should end up with the same new compound. If not, then they're not equivalent protons. *What makes protons have different resonance frequencies depends on what atom they're close to. *NMR measures the chemical shift relative to a standard called TMS (tetramethylsilane) in unit of ppm. *The more "different" two protons are, the farther their chemical shifts 3) Spin-spin splitting: Are you peaks singlets, doublets, triplets, etc? -the magnetic field felt by a proton is influenced by surrounding protons. Nearby protons that are nonequivalent to the proton in question will cause a splitting in the observed NMR signal. The signal will be split into n+1 lines, where n is the number of nonequivalent, neighboring (interacting) protons. Singlet (0 neighbors), doublet (1 neighbor), triplet (2 neighbors), etc *Protons across single and aromatic bonds get split approximately the same. *Protons across double bonds get split farther apart. (molecular structure and absorption spectra)

Doppler effect → Situations where the observed frequency could be either higher or lower than the actual:

Source moving toward the observer, but the observer is moving away from the source (use minus on top and bottom of equation) Source moving away from observer, but the observer is moving toward the source (use plus on top and bottom of equation) (sound)

The net force and ______ always point in the same direction.

acceleration (Force)

Displacement:

change in position; does not matter about the path taken (only cares about start and finish); vector quantity; can be described by: Δd=xf-xi, sometimes displacement is written as Δs instead of Δd -displacement gives you the net distance traveled. You can have a positive or negative displacement -units are in meters Ex, if a sprinter runs 400m around a circular track and returns to her starting point, then her total displacement is 0. Her distance is 400m. (translational motion)

Define work. In what units is it measured? It is a vector or is it a scalar?

work by force F acting over displacement d, W=FdcosΘ. It is a scalar, measured in J, where 1J=1Nm

State the Heisenberg Uncertainty Relation

∆x∆p≥h/2π. The better one knows the position of a particle, the less one knows its momentum and vice versa

You have two frictionless, massless pulleys. If you have enough force to lift a 40kg object w/out any pulleys, what is the maximum mass of the couch that can be raised w the pulley system?

*1st, I can lift 40kg, what's the force of this? So, F=ma → F=(40kg)(10) → F=400N *2nd, two pulleys means you can exert 4x the force. So, F=(400N)(4) → F=1600N *3rd, the question wants to know how many kg you can lift, not the force. So, F=ma → 1600N=m(10) → m=160kg (Force)

Do concave or convex mirrors focus light?

*Concave mirrors can focus; they are converging mirrors; they focus light rays to the the focal point. *Convex mirrors cannot focus; they are diverging mirrors; they diverge light rays. When drawing a ray diagram, you have to extrapolate them to find their right focal point (geometrical optics)

Consider a charge +q, initially at rest near another charge, -Q. How would the magnitude of the electrical force on +q change if -Q were moved away, doubling its distance?

*Coulomb's law is an inverse square law, Felectical∝1/r², so if r increases by 2, you get 2², so Felectrical decreases by a factor or 4, Felectical∝1/4 (Electrostatics)

Heat of vaporization:

*amount of heat that must be absorbed to go from l → g, +ΔHvap *amount of heat that is released when going from g → l, -ΔHvap

At a distance of 1m, the intensity level of a soft whisper is about 30dB, while a normal speaking voice is about 60dB. How many times greater is the power delivered per unit area by a normal speaking voice than by a whisper?

*sound level, 𝜷: 30dB whisper and 60dB talking, difference of 30, (10+10+10) *intensity, I: (10)(10)(10) → 1,000 times greater (sound)

Oxidation is an ________. Reduction is a __________.

-oxidation is an increase in charge -reduction is a decrease in charge (electrochemistry)

Compare period and frequency:

-period, T, is just how many seconds for one cycle -frequency, f, is just how many cycles in one second *period and frequency are reciprocals f=1/T and T=1/f Ex, a wave w a period of 2 seconds. Since the wave completes one cycle every 2 seconds, then it's frequency is one half, or 0.5Hz. (periodic motion)

Solubility rules of electrolytes:

Electrolytes that are soluble in water= -group 1 ions, like Na+, K+, H+ -ions w a small charge (charge of -1 or +1), like NO₃⁻, CH₃COO⁻, ClO₄⁻ *polar means it has a net dipole; not symmetrical in shape *exception: Ag+ is insoluble in water Electrolytes that are usually insoluble in water= -ions w a large charge (charge of +2, +4, -2, etc), like Ag+, Pb²⁺, Pb⁴⁺, Hg₂²⁺, Hg²⁺, CO₃²⁻, PO₄³⁻, S²⁻ *nonpolar means it does not have a net dipole; symmetrical in shape (gas phase)

Compare BP in your legs vs arms:

BP is lower in your arms, higher in your legs (circulatory system)

Basic oxide:

Basic oxides are always oxides of metals. They combine with water to form bases (which are usually called metal hydroxides). Na2O, MgO, CaO, FeO and CuO are examples of basic oxides. Ex: Na2O + H2O --> 2NaOH (the periodic table; electronic structure)

Why does an object look green in color?

Bc green light is being reflected off the object. Blue and red light are being absorbed (geometrical optics)

Define beats. How is the beat frequency calculated?

Beats are the periodic variation in amplitude of the wave formed by the superposition of two sound waves of diff frequencies, fbeat=|f₁-f₂|

What kind of reaction occurs at the anode of an electrochemical cell? at the cathode?

Oxidation occurs at the anode, and reduction occurs at the cathode

Virtual image:

To the observer, the image appears to be behind the mirror (not in real space), or behind the lens (image on same side as the object) *virtual images are always ERECT (non inverted/upright), and cannot be cast on a screen *always has a -i *Diverging (concave lens and convex mirror) only create virtual, erect images *Converging (convex lens and concave mirror) can create both real, inverted and virtual, erect images (geometrical optics)

Units of pressure:

Pascal, Pa pascal=N/m^2, newtons per meter squared

The specific heat of liquid water is 1cal/g℃. The specific heat of copper is 0.09cal/g℃. So, if you have a 1g sample of water and a 1g sample of copper and each absorb 10 calories of heat, what is the resulting temp change?

Water, q=mcΔT → ΔT = q/mc → 10cal // (1g)(1cal/g℃) → 10℃ Copper, q=mcΔT → ΔT = q/mc → 10cal // (1g)(.09cal/g℃) → 111℃ **Larger specific heat means more heat needs to be added to see a temp change (gas phase)

Name two important differences between light behaving like a wave and behaving like a particle that give rise to seeming contradiction within the wave-particle duality theory of EM radiation

Waves interfere, diffract, and polarize, whereas particles do not. The energy delivered by a wave depends upon amplitude and intensity (brightness), whereas the energy delivered by a particle depends upon frequency (color)

Define simple harmonic motion, amplitude, period, and frequency. What is the relationship between period and frequency?

SHM=oscillatory motion, where restoring force α displacement; amplitude A=maximum displacement from equilibrium; period T=time required for oscillator to complete one full cycle; frequency f=# of cycles per unit time; f=1/T

Sometimes waves do not seem to move. Rather, they just vibrate in place. This concept is called a _______.

Standing Wave *Under certain conditions, waves can bounce back and forth through a particular region, effectively becoming stationary. (periodic motion)

Binding energy is due to the _______.

Strong force. (atomic nucleus)

under what conditions does a magnetic field exert a force on a charge? What effect can it have? What is the work done by the magnetic force on a charge?

When the charge moves neither parallel nor antiparallel to the field (if a component of its velocity is perpendicular to the field). Magnetic force can only change the direction of velocity and can do no work on a charge.

A box of mass m slides down a frictionless ramp w incline angle θ. What is its acceleration?

a=mgsinθ

name the three types of nuclear decay from least to most damaging to living tissues

alpha < beta < gamma in order from least damaging to most damaging

Charge is quantized:

an object can become charged, ionized, only by losing or gaining electrons. These electrons can't be "sliced" into smaller pieces w fractional amounts of charge; atoms gain or lose a whole number of electrons, so charge is quantized. This is why electric charge is denoted by the letter "q," where, q=n(+/- elementary charge). For any object, its charge, (q), is given by the whole number of electrons (n), times the elementary charge of an electron, (1.6x10⁻¹⁹ C). (Electrostatics)

Define equilibrium:

an object is in equal if Fnet=0 and 𝛕net=0

Plane mirror:

an ordinary, flat mirror. If you put an object in front of it, it will produce a virtual image that is the same distance behind the mirror as the object is in front of it. The image will be the same size as the object and upright. Plane mirror= the mirror you use everyday to get ready (geometrical optics)

Superposition of charge:

enables determination of Felectrial when there are >2 charges in the system. The net electric force on a charge, (q), due to the collection of other charges, (Q's), is equal to the sum of the individual forces that each of the Q's alone exert on q *we can calculate the effect of several charges by considering them individually and then just adding the resulting forces For ex, if q1 and q2 exert some force on q3, you can determine the magnitude of force on q3 by: F1on3=k |q1q3| /r² F2on3=k |q2q3| /r² So, Ftotalon3=F1on3+F2on3 (Electrostatics)

Sublimation:

going from solid → gas *conditions for sublimation can be found along the solid-gas boundary on a given phase diagram

Describe how a force can provide no torque

if the line of action passes through the pivot point, then the force will produce no torque

Current:

the amount of charge that passes a certain point per time. Expressed by: I=Q/t, where I is the current, Q is the amount of charge that passes a certain point, and t is time. *the units for current is Amp, (A). Coulombs of charge per second *the direction of current is taken as the flow of positive charges (Circuit Elements)

Law of reflection:

when a beam of light strikes the boundary between two transparent media, some of the light will be reflected from the surface. The angle of reflection is equal to the angle of incidence, this is known as the "law of reflection." θ = θ' *the angles of incidence and reflection are measured w reference to a line that's perpendicular to the surface, called "the normal." So, the angle of incidence and the angle of reflection are the angles that the incident and reflected rays make w the normal, not w the surface. (geometrical optics)

Solve 10⁻⁷/10⁻¹³

(10⁻⁷)(10¹³) = 10⁶ power divided by a power, bring bottom number to the top and change exponent sign. Treat it as power times a power, add the powers

Heat of fusion:

*amount of heat that must be absorbed to go from s → l, +ΔHfus *amount of heat that is released when going from l → s, -ΔHfus

Doppler effect → situations where the observed frequency is higher than the actual:

**source and detector are moving closer together. Either: Source moving toward stationary observer Observer moving toward stationary source Source and observer both moving toward each other (sound)

Doppler effect → situations where the observed frequency is lower than the actual:

**source and detector are moving farther apart. Either: Source moving away from stationary observer Observer moving away from stationary source Source and observer both moving away from each other (sound)

Electric potential vs electrical potential energy:

*Electric potential= a property of points in space. At any point P that's a distance r from Q, the electric potential at P is given by ɸ=k Q/r. Units of volts, V. *Electric potential energy= a property of a system. Two charges in the vicinity of each other have PE, given by ΔPEelectric = qΔɸ = qVoltage. Units of Jewels, J. Note: voltage is just the electrical potential difference (Electrostatics)

The plates of a parallel plate capacitor are separated by a distance of 2mm. The device's capacitance is 1µF. How much charge needs to be transferred from one plate to the other in order to create a uniform electric field whose strength is 10⁴ V/m?

*we know Q=CV and V=Ed, so we can get Q=CEd → Q= (1x10⁻⁶ F)(1x10⁴)(2x10⁻³m) → 2x10⁻⁵ C = Q (Circuit Elements)

The magnitude of the electric field at a distance r from a source charge +Q is equal to E. What will be the magnitude of the electric field at a distance 4r from a source charge +2Q?

*we know that E= k Q/r² → E= k (2Q)/(4r)² → E= k 2Q/16r → so Eα1/8 **So, if Q is changed to 2Q and r to 4r, then E decreases by a factor of 8 (Electrostatics)

In general, if you looked into a plane mirror, a concave mirror, and a convex mirror, what would you see?

-A plane mirror will produce an image of the same size. -A Concave mirror will produce magnified image and your face will look much bigger. Makeup mirrors -A Convex mirror will produce diminished image and your face will look much smaller. (geometrical optics)

Which is a possible excited state configuration for Na? A)1s2 2s2 2p6 3s2 B)1s2 2s2 2p6 3p1

-Choice B is a possible excited state configuration for Na. -choice A is not possible, it has too many e- (atomic nucleus)

Conservation of mass and charge with radioactive decay:

-Conservation of mass dictates that total atomic weight before the decay equal the total atomic weight after. -Conservation of charge dictates that the total atomic number before the decay equal the total atomic number after. *energy is never created or destroyed (atomic nucleus)

In acid-base titrations, we think of titration curves in terms of _________. In redox titrations, we think of titration curves in terms of __________.

-In acid-base titrations, we think of titration curves in terms of pH or pOH vs volume of titrant added -In redox titrations, we think of titration curves in terms of cell potential vs volume of titrant added

Two main types of electrochemical cells:

-galvanic cell/voltaic cell -electrolytic cell (electrochemistry)

Isotopes of hydrogen:

1) Hydrogen-1 or ¹H, called protium. Contains 1p+, 0n, 1e- *the most common isotope of hydrogen. 2) Hydrogen-2 or ²H, called deuterium (D), heavy hydrogen. Contains 1p+, 1n, 1e- 3) Hydrogen-3 or ³H, called tritium (T). Contains 1p+, 2n, 1e- 4) there is also hydrogen-4, hydrogen-5, hydrogen-6, and hydrogen-7. These are highly unstable. They contain 1p+, Xn, 1e-

The four fundamental forces/universal forces of nature, in order from strongest to weakest:

1) The strong force: also called the nuclear force. It is the strongest of all the four forces, but it only acts at subatomic distances. It binds nucleons together (holds n and p+ together in the nucleus). 2) electromagnetic force: about one order of magnitude weaker than the strong force, but it can act at observable distances. Includes electric and magnetic effects, such as repulsion between like electrical charges or the interaction of bar magnets. It can be attractive or repulsive. Binds atoms together; Allows magnets to stick to your fridge; It is responsible for the fact that you are not falling through your chair right now. F=k |q1q2| /r^2 3) weak force: roughly 10 orders of magnitude weaker than the strong force. It is the the mechanism of interaction between subatomic particles. Responsible for radioactive decay (n --> p+ + e-, etc) 4) gravity: roughly 50 orders of magnitude weaker than the strong force. Responsible for weight (not mass!). Also, responsible for planet orbits. Gravitational force is weak, but very long ranged. Always attractive. *F=G mM/r^2 (Electrostatics)

Atomic mass vs mass number:

1) atomic mass, is the atomic weight (the weighted average mass of an atom of an element based on the relative natural abundance of that element's isotopes). It is given on the periodic table. 2) mass number, A, is the total number of protons and neutrons in the atom's nucleus. *For ex, H has three natural isotopes ¹H, ²H, and ³H. Each isotope has a different mass number. However, they all have approximately the same atomic masses, ~1amu ¹H has 1 proton. Its mass number is 1. ²H has 1 proton and 1 neutron. Its mass number is 2. ³H has 1 proton and 2 neutrons. Its mass number is 3. (atomic nucleus)

List common 3-D shapes and how to calculate their surface area and volume:

1) box SA=2lw+2lh+2wh Volume: V=lwh 2) cylinder SA=2π r(r+h) Volume: V=π r²h 3) sphere SA=4πr² Volume: V=4/3 πr³

Periodic trends:

1) effective nuclear charge: shielding *across row effective nuclear charge increases *down group effective nuclear charge does not change 2) electrostatic attraction: how much the positively charged nucleus is pulling on electrons *across row electrostatic attraction increases *down group electrostatic attraction decreases 3) ionization energy: energy needed to remove an electron *across row ionization energy increases *down group ionization energy decreases 4) electron affinity: amount of energy released when an element gains an electron *across row e- affinity increases (more negative) *down group e- affinity decreases (less negative) 5) electronegativity: how much an element hoards electrons in a covalent bond *across row electronegativity increases *down group electronegativity decreases **some variations 6) atomic radius: size *across row atomic radius decreases (gets smaller) *down group atomic radius increases (gets larger) **you can also look at ionic radius for ions (periodic table; group and row)

A cannonball is shot from ground level w an initial velocity of 100m/s at an angle 30 degrees to the ground. How high will it go? What is its velocity at the top of its path? What is the total time the projectile is in the air? How far did the projectile travel?

1) how high it will go; asking for the vertical displacement (y direction) Displacement y= 125m 2) what is its velocity at the top we know at the top, the vy=0 and the vx is constant throughout the flight. So, just solve for velocity in x direction. Velocity = 85m/s 3) what is the total time the projectile is in the air Use the vertical component only (y direction) t=10sec 4)how far did it go; asking for the horizontal displacement (x direction) First get the time in the air by the vertical component. Then use the horizontal component (speed)(time) of flight *this is faster/easier than using one of the Big Five Displacement x= 850m (translational motion)

What are the three fundamental particles of matter, and which determines the identity of an element?

1) p+, determines element identity 2) n 3) e-

Solve (10⁻³)(10¹⁷)

10¹⁴ power times a power, add the powers

Voltage, vs current vs resistance:

1) voltage= measured in Volts. The "push" from a battery *electric potential difference is the difference in electric potential between two points 2) current (I)= measured in Amps, (coulombs of charge per second), I=q/t. The flow of charge in a circuit 3) resistance= measured in Ohm (Ω). Resists the flow of current. (electrochemistry)

Balancing redox reactions, key points:

1)determine the oxidation number of each element 2)write and balance each half reaction (balance atoms and charge) -only include species of interest (those which undergo a change in oxidation state). Does not include spectator ions -anything not covalently attached to the atom is not part of the species of interest -under acidic conditions, add H2O to the side that needs the oxygen atom, then add H+ to the other side -under basic conditions, add 2OH- to the side that needs the oxygen atom, then add H2O to the other side 3)recombine the half reactions -multiple each half reaction by a factor, such that when you add them together, the e- will cancel -cancel out identical species on opposite sides of equation -combine identical species on same side of the equation -add back in spectator ions -check to make sure every element has a neutral charge

Times tables, 6:

6x1 = 6 6x2 = 12 6x3 = 18 6x4 = 24 6x5 = 30 6x6 = 36 6x7 = 42 6x8 = 48 6x9 = 54 6x10 = 60 6x11 = 66 6x12 = 72 6x13 = 78 6x14 = 84 6x15 = 90 *And, 6² = 36

Solve (6⁻³)⁴

6⁻¹² power raised to a power, multiply the powers

Times tables, 7:

7x1 = 7 7x2 = 14 7x3 = 21 7x4 = 28 7x5 = 35 7x6 = 42 7x7 = 49 7x8 = 56 7x9 = 63 7x10 = 70 7x11 = 77 7x12 = 84 7x13 = 91 7x14 = 98 7x15 = 105 *And, 7² = 49

DC Circuits:

A Direct Current circuit is a circuit that Electric Current flows through in one direction. *the simplest circuit consists of a voltage source (most commonly a battery), a connecting wire between the terminals of the voltage source, and a resistor. (Circuit Elements)

In the absence of a salt bridge, charge separation develops. The anode develops a positive charge and the cathode develops a negative charge, quickly halting the flow of electrons. In this state, the battery resembles:

A capacitor *stores equal and opposite charge (stores electrical energy) (galvanic cell) (electrochemistry)

What is a magnifying glass?

A converging/convex lens. It produces a virtual, erect, larger image when o<f, object is in front of your focal point (geometrical optics)

Composition by percent mass:

A molecules empirical formula or molecular formula can be used to determine the molecule's percent mass composition. Ex, find the mass composition of C, H, and N in C₄H₄N₂. first, using the empirical formula will be easier. So, C2H2N. And the empirical MW is 40. So each elements contribution to the total mass is: %mass = mass of species of interest/total mass %C= 2(12)/40 → 12/20 → 60/100 → 60% %H = 2(1)/40 → 1/20 → 5/100 → 5% %N = 14/40 → 7/20 → 35/100 → 35%

What generates a magnetic field? In what units is it measured?

A moving charge generates a magnetic field, B. The units for B is the tesla, where 1T=1Ns/Cm

What is a particle of electromagnetic radiation called? What is its energy?

A photon, it has energy E=hf

An antioxidant is another word for what?

A reducing agent! Antioxidant= anti-oxidation; Prevents oxidation by reducing something.

Simple harmonic motion of a pendulum:

A simple pendulum involves a mass attached to a string of length L which moves in an oscillating motion, back-and-forth. -the displacement of the mass is the angle it makes w the vertical. The vertical is the equilibrium position where θ=0. -has a restoring force, which is proportional to displacement. Here, the restoring force is gravity, which is equal to mgsinθ. -In order for a pendulum to undergo simple harmonic motion, the displacement from equilibrium, theta must be small. -has a period and frequency, which DOES NOT depend on amplitude or mass of the swinging object. Period and frequency only depend on length of the string and gravitational force, (Fg). This is expressed by: f=1/2𝝅 √g/l T=2𝝅 √l/g or ω=√g/l *where g is gravity, 10Nkg and l is the length of the string. ω is the angular frequency -the pendulum oscillates faster when gravity is large and when the string is short -at the equilibrium position, PE=0, KE=max -at max displacement, PE=max, KE=0 -at any point, PE+KE=maximum PE=maximum KE=constant -the PEmax=mgA, where A is the maximum height that the pendulum can gain during a swing -the KEmax=1/2mv² at the equilibrium position (periodic motion)

Second harmonic:

A standing wave composed of one full wavelength. Where ƛ=L. It has a total of three nodes and two antinodes. (periodic motion)

A substance's specific heat is an _________.

A substance's specific heat, c, is an intrinsic property of that substance and tells us how resistant it is to changing its temp.

Perfectly inelastic collisions:

A type of inelastic collision where things stick together after the collision. Total momentum is conserved, but total KE is not. Perfectly inelastic collisions lose >>> KE compared to inelastic collisions. (Equilibrium)

The density of seawater is 1025 kg/m³. Consider a point X that's 10m below the surface of the ocean. A)what's the gauge pressure at X? B)If the atmospheric pressure is 1.015x10⁵ Pa, what is the total pressure at X? C)consider a point Y that's 50m below the surface. How does the gauge pressure at Y compare to the gauge pressure at X? How does the total pressure at Y compare to the total pressure at X?

A)the gauge pressure at X is: Pgauge=⍴fluidgD → (1025kg/m³)(10)(10) → 1.025x10⁵ Pa B)the total pressure at X is: Ptotal= Patm + Pgauge → 1.015x10⁵ Pa + 1.025x10⁵ Pa → 2.04x10⁵ Pa = Ptotal C)first, since Pgauge is proportional to D, an increase in D by a factor of 5 will mean the gauge pressure will also increase by a factor of 5. So, gauge pressure at Y will be 5(1.025x10⁵ Pa) → 5.125x10⁵ Pa. *Ptotal=Patm + Pgauge → 1.015x10⁵ Pa + 5.125x10⁵ Pa → 6.14x10⁵ Pa = Ptotal ****Notice that total pressure is NOT proportional to depth (fluids)

A particle of mass 3kg moves w a speed of 5m/s around a circle of radius 60cm. What is the magnitude of its momentum? Its angular momentum?

A)the particles linear momentum is p=mv → p=(3kg)(5m/s) → p=15 kgᐧm/s B)the angular momentum is L=rmv → L=(.6m)(3kg)(5m/s) → L=9 kgᐧm²/s (Equilibrium)

An atom with 7 neutrons and a mass number of 12 is an isotope of what element?

A=12, N=7, Z=5 *the element must be boron (atomic nucleus)

Period:

Abbreviated as "T". the time it takes for one cycle, in seconds. One cycle= returning to the same position and velocity. Period is expressed by: T= 1/f, where f is the frequency in Hz, cycles/second -units of period is the second -the period is constant over time -the period is independent of amplitude (periodic motion)

Frequency:

Abbreviated as "f". The rate, or how many cycles per second. Expressed by: f= 1/T, where T is the period in seconds -units of frequency is the hertz, cycles/second -sometimes frequency is given in rpm, (revolutions per minute). When this happens, convert rpm to: *cycles per second, Hz, (1rev/1min)(1min/60seconds) → x revolutions/60seconds *radians per seconds, rad/sec, (1rev/1min)(2𝜋rad/1rev)(1min/60seconds) (periodic motion)

Newton's 3rd law describes _______.

Action and reaction pairs. Objects exert equal and opposite forces on each other (Electrostatics)

The mirror/lens equation:

Allows you to answer questions such as: where is the image? is the image real or is it inverted? 1/o + 1/i = 1/f *o is the object's distance from the mirror or lens (always positive) *i is the image's distance from the mirror or lens i is positive if the image is real i is negative if the image is virtual *f is the focal length f is positive for converging systems f is negative for diverging systems Real images are always inverted. Virtual images are always erect. (geometrical optics)

Electric potential:

Also called "absolute potential." The amount of energy per charge that something possesses. *a scalar field created by a source charge, Q, that permeate the space around it. At any point P that's a distance r from Q, we say that the electric potential at P (also called the absolute potential) is the scalar given by: ɸ=k Q/r, with units of volts, V, or Joule per coulomb, J/C. *the volt is just energy/charge *potential allows you to answer questions about scalar quantities, like energy, work, or speed. *the electric potential is the same at every point that's a distance r from Q, (equipotentials). Equipotential lines are places where the potential is the same. Equipotential lines are always perpendicular to electric field lines *as you move far away from the source charge, (as r → ∞), the potential decreases to zero *the electric potential, ɸ, can be positive, negative, or zero *if you have a source charge, +Q, then the values of the potential due to this source charge will also be positive. If you have a source charge, -Q, then the values of the potential due to this source charge will also be negative. The sign of the potential is not an indication of a direction, bc remember, potential is a scalar (thus it has no direction) *if there are multiple charges contributing to the potential, then sum them together to find the total potential at a point (Electrostatics)

Angular frequency:

Also called "angular velocity." The rate, in how many radians per second, (rad/s). Remember, one circle contains 2𝝿 radians. The angular velocity is expressed as: ω=2𝝿f, where f is the frequency in Hz, (cycles per second), given by f=1/T The angular frequency is larger than regular frequency (in Hz) by a factor of 2𝝿. Hence, 1Hz≈6.3 rad/sec (periodic motion)

Gauge pressure:

Also called "hydrostatic gauge pressure." Pressure that is exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic gauge pressure only takes the pressure due to the fluid into account ('hydrostatic' bc the fluid is at rest, and 'gauge pressure' bc we don't take the pressure due to the atmosphere into account). Gauge pressure is expressed by: Pgauge=⍴fluidgD, where ⍴ is density of the fluid, g is acceleration due to gravity, and D is depth of the object. Remember, this equation only tells you the force of the fluid on an object. Also, remember, pressure is expressed in pascals! -gauge pressure is proportional to both depth and the density of the fluid. It increases in proportion to depth measured from the surface bc of the increasing weight of fluid exerting downward force from above -gauge pressure at the surface= 0 bc the depth=0 **Note: the total pressure or absolute pressure takes the gauge pressure and atmospheric pressure into account. Total pressure is not proportional to either depth or density. (fluids)

Newton's 1st law:

Also called "law of inertia." If the net force, Fnet, acting on an object is zero or if there are no external forces, then its velocity will not change. -an object at rest remains at rest -an object in motion remains in motion. It will continue to move w constant velocity in a constant direction. -no net force= no acceleration -this property of objects, their natural resistance to change in their state of motion, is called inertia -mass is the measurement of an object's resistance to acceleration (or its inertia) (Force)

Insulator:

Also called a "dielectric." Materials in which charges cannot move freely. Electrons are tightly bound to their atoms and thus are not free to roam through the material. Examples of insulators = rubber, glass, wood, paper, plastic -insulators/dielectrics can still become polarized (slightly positive and slightly negative). This is just electrostatic induction. Induction does not involve any type of conduction. (Electrostatics)

Units of current:

Ampere, A

A 2kg mass is attached to a massless, 0.5m string and is used as a simple pendulum by extending it to an angle θ=5° and allowing it to oscillate. Which of the following changes will increase the period of the pendulum? A)replacing the mass w a 1kg weight B)changing the initial extension of the pendulum to a 10° angle C)replacing the string w a 0.25m string D)moving the pendulum to the surface of the moon

Answer=D (periodic motion)

Cell diagram:

As a convenient substitution (so you don't have to draw out a galvanic/voltaic cell), you can use a cell diagram to show the parts of an electrochemical cell. For ex, Zn(s) | Zn²⁺ (aq) || Cu²⁺ (aq)| Cu(s) *We place the anode on the left and cathode on the right, "|" represents the boundary between the two phases, and "||" represents the salt bridge. Another way of looking at it: Anode | Anodic solution || Cathodic solution | Cathode (galvanic cell) (electrochemistry)

Define each periodic trend

Atomic radius: extent of the valence electrons of an atom Ionization energy: energy required to remove a mole of valence electrons from a mole of gaseous atoms of a given element Electron affinity: energy associated with adding a mole of electrons to the valence shell of a mole of gaseous atoms of a given element Electronegativity: a measure of the amount of "pull" an atom has on shared valence electrons in a bond Acidity: the tendency for a molecule to give up a hydrogen ion

Most common power-of-ten prefixes:

Atto (a), 10^-18 Femto (f), 10^-15 Pico (p), 10^-12 nano (n), 10^-9 micro (µ), 10^-6 milli, (m), 10^-3 centi (c), 10^-2 Deci (d), 10^-1 Deca (da), 10^1 Hecto (h), 10^2 kilo (k), 10^3 mega (M), 10^6 Giga (G), 10^9 Tera (T), 10^12 Peta (P), 10^15 Exa (E), 10^18

The ground state e- configuration of any element can be determined by following three rules of electron filling. What are they and how do they determine the location of electrons in an atom?

Aufbau principal (fill lower energy levels and sublevels before adding e-'s to higher energy levels or sublevels) Hund's Rule (half filled orbitals of equal energy before pairing e-'s in any one orbital in a given subshell) Pauli exclusion principal (there is a maximum of 2e-'s per orbital, and they must have opposite spins)

Which process requires energy (is endothermic), breaking a bond or forming a bond?

Breaking bonds is endothermic. Forming bonds is exothermic

Compare simple harmonic motion of a spring vs pendulum:

BOTH: -at the equilibrium position, PE=0, KE=maximum -at max displacement, PE=maximum, KE=0 -at any point, PE+KE= maximum PE= maximum KE= constant -constant PEmax *1/2kA² for a spring *mgA for a pendulum -constant KEmax = 1/2mv² at the equilibrium position -maximum velocity occurs at the equilibrium position -has a restoring force (exerted by either the spring or Fg) which is proportional to the displacement -period and frequency are not dependent on amplitude (the displacement from equilibrium) SPRING: -period and frequency depend on mass and the spring constant, (k) PENDULUM: -period and frequency depend on length of the string and gravitational force, (Fg) -period and frequency do not depend on mass (periodic motion)

one type of nuclear decay has three different modes. What are they?

Beta decay 1) β- (normal decay) 2) β+ (positron emission) 3) electron capture

What happens to BP when you elevate a blood vessel?

Blood pressure is lower when you elevate a blood vessel (think physics, P = ρgh, where h is the depth - raising your arm is like taking it to shallower water). *when you raise your arm, less blood is flowing to it, lower "cardiac output" (circulatory system)

Put the vessels of the cardiovascular system in order by pressure characteristics:

Blood pressure of arteries > arterioles > capillaries > venules > veins *Blood squirts from arteries, flows from veins, and oozes from capillaries. *Blood pressure is highest in the arteries (specifically the aorta) because the heart pumps directly into the aorta. The elasticity of arteries causes blood to flow even when the heart is resting between pumps (this is why your diastolic blood pressure is not zero) *Blood pressure is lowest in the veins (specifically the vena cava). Veins operate at a lower blood pressure, since the blood has lost considerable pressure traveling through the arteries and capillaries. Therefore, veins are less muscular than arteries. Also, many veins must transport blood from the lower body up to the heart. This requires the blood to flow against gravity. To facilitate this upward flow, many veins have one-way valves that prevent blood from flowing back and pooling in the lower extremities. (circulatory system)

What can you say about the speed and energy regarding red photons and blue photons traveling through vacuum?

Blue light travels at the same speed as red light and carries more energy (geometrical optics)

Compare CH₄ vs CI₄ at room temperature:

Both are nonpolar molecules, so both only have london dispersion forces. However, iodine is much larger in size compared to H (has more e-'s), therefore, it has more LDF's. Thus, CH₄ is a gas while CI₄ is a liquid or solid at room temperature (gas phase)

Describe the resistance and resistivity of two aluminum wires where one is long and thin and the other is short and thick.

Both wires have the same resistivity (made of the same material), but the wires have diff resistances. The long thin wire has a greater resistance compared to the short thin wire, bc R is proportional to L and inversely proportional to A (Circuit Elements)

Define center of mass. How is this point located?

CM= point where all the object's mass can be considered to be concentrated=point that behaves as if the object were a single particle=the balance point (m1x1+m2x2)//m1+m2

Describe the work done by centripetal force:

Centripetal force does zero work. The Fc is always perpendicular to motion. Cos(90)=0 (Work)

Give two examples of elements that do not obey the Aufbau principle

Chromium and its family member or copper and its family members.

You can only accurately titrate something using iodine when going from _______.

Color to clear, I₂ → 2I- *it does not work the other way around. Endpoint is reached when solution turns blue in color

Define conductor and insulator, and give examples of each

Conductor= electric charges (free electrons) can move easily (metals). Insulator= electric charges cannot move easily (rubber, wood, glass, etc)

Total electric charge is always _______.

Conserved. If something is losing electrons, something else must be gaining electrons. The total amount of charge before any process must always equal the total amount of charge after process. You can't create or destroy charge, you can only transfer charge from one source to another. (Electrostatics)

Convex lens ray diagram:

Converging; same as concave mirrors Tend: real/inverted and small, and getting bigger along the way until it becomes virtual/upright. (geometrical optics)

Passenger side rear-view mirrors in a cars are:

Convex mirrors. "Objects in mirror are closer than they appear." This is because the objects are made smaller by the mirror, so they appear farther away! *convex mirror is used as the rear mirror of the vehicles because, the convex mirror enables a driver to view large area of traffic behind him by forming a small image of the vehicles. (geometrical optics)

Define electric current. In what units is it measured? What is the direction of conventional current? What causes current?

Current, I: net charge flowing per unit time. Measured in Amps, where 1A= 1C/s. By convention, current flows in the direction that positive charge carries would move. Current is caused by a voltage, a difference in electric potential

Define gauge pressure and give the formula for hydrostatic gauge pressure

Gauge pressure= total pressure - atmospheric pressure Hydrostatic gauge pressure=⍴fluidgD

Speed of light in a vacuum:

EM radiation travels fastest in a vacuum, at a velocity equal to c=3x10⁸ m/s. All EM waves, regardless of frequency, travel through a vacuum at this speed. *The wave equation, v=ƛf, is also true for EM waves. When EM waves travel through a vacuum, the equation becomes c=ƛf *light slows down when it travels in a medium other than a vacuum (geometrical optics)

Electric field for a cylinder:

Electric field for a cylinder runs radially perpendicular to the cylinder, and is zero inside the cylinder. (Circuit Elements)

Electric field for wires:

Electric field for wires runs radially perpendicular to the wire. (Circuit Elements)

Electric field in a capacitor:

Electric field in between a capacitor is uniform until it reaches the ends of the capacitor (where it starts to bend outwards). (Circuit Elements)

Define buoyant force and state Archimedes' Principle

Fbuoyant=net upward force exerted by a fluid on an object Archimedes' principle, Fbuoyant=weight of fluid displaced=(⍴fluid)(Vsubmerged)(g)

A 100kg skier's knee can withstand a lateral torque of 500Nᐧm before dislocating. As the skier loses control going around a corner, one ski comes up off the snow and the other boot and lower leg remain vertical, such that the knee starts to bend laterally. If the distance from the skier's knee to his center of mass is 1m, at what angle, theta, from the vertical, will the knee dislocate due to the torque of gravity?

Fg= (100)(10) → 1000N 𝛕=rFsinθ → sinθ = 𝛕/rF → sinθ = 500/(1)(1000) → sinθ = .5 → 30° (Equilibrium)

Which three periodic trends follow the same pattern? Why do these three trends all agree?

First ionization energy, electron affinity, and electronegativity. They are all inversely related to atomic size

In whole blood fractionation, in which blood is centrifuged to separate it into its component parts, how does the centripetal acceleration on a RBC at a distance d from the axis of rotation compare to the centripetal acceleration felt by an equal mass of plasma at a distance d/2 from the rotor?

First, we know that velocity = Δx/Δt → velocity= 2𝝅 r/t *the change in x is just circumference of the circle, so 2𝝅r Second, ac=v²/r → ac= (2𝝅 r)²/rt² → ac= 4𝝅^2r/t² *here, 4, 𝝅, and t are all constants, so we see that ac α r Answer: a RBC at a distance d from the axis of rotation experiences twice the centripetal acceleration compared to a RBC at a distance d/2 from the axis of rotation WHEN YOU DOUBLE THE DISTANCE, YOU DOUBLE THE CENTRIPETAL ACCELERATION (Force)

Define normal force. Is the magnitude of the normal force on an object always equal to the object's weight?

Fn is the component of contact force. It is exerted by a surface that is perpendicular to an object The normal force on an object is NOT always equal to the objects weight. Ex: a book sitting on a table, usually Fn=Fw. However, what if you begin to push downward on the book? Now, the Fn=Fw+Fpush *or, What if you are pushing the book against a wall, so that it does not fall? In that case, the book pushes against the wall and the wall pushes back. That interaction is the normal force and acts on both the book and the wall. (Of course, your hand also pushes against the book - and the book pushes back on your hand.) But none of those forces were equal to the gravitational force on the book. (What kept the book from falling was friction.) *or, stand up; Now jump straight up. How did you do that? Well, you crouched a bit, then straightened your legs while pushing against the floor. Because of that added force, you increased the normal force on the floor making it greater than your weight. And that means that the normal force of the floor against your feet was also greater than your weight. And since the net force on you was upward, you accelerated upward. That is, you jumped because the normal force was greater than your weight.

A box of mass m slides down a ramp w incline angle θ. What is the normal force on the box?

Fn=mgcosθ

Newton's 2nd law:

Fnet= ma. If there is a net force acting on an object, the object will have an acceleration in the direction of the net force. -both force and acceleration are vectors, they have a direction -mass is a positive scalar, cannot have a negative mass -therefore, Fnet and acceleration point in the same direction, Fnet ∝ acceleration -if Fnet=0, then a=0. Velocity is constant, but not necessarily zero -units for force = newton = 1kg·m/s^2 Note: a force of 1kg·m/s² is called 1 newton. 1 newton is about the force an apple exerts on your hand while holding it (Force)

Conservation of linear momentum:

For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. Two objects exert equal and opposite forces on each other (newton's 3rd law). J₁on₂ = -J₂on₁, when object 1 comes in contact w object 2, they exert equal and opposite impulses on eachother Δp₂ = -Δp₁, when object 1 comes in contact w object 2, each object undergoes a change in momentum, which is equal and opposite to each other -thus, the total change in momentum of the system is zero. Momentum is conserved, it does not change. *note: the individual momenta of the objects in the system certainly can change, but always in such a way that their sum, the total momentum of all the objects, doesn't change. -The law of conservation of linear momentum is given by: Δpsystem = 0 or total p₀ = total pf or m₁v₁ + m₂v₂ = m₁v'₁ + m₂v'₂ *total momentum of 2 objects before a collision = total momentum of 2 objects after a collision -momentum is a vector, so be sure to assign one direction as positive and one direction as negative when adding individual momenta when calculating the total momentum Ex, the momentum of a bomb at rest = the vector sum of the momenta of all the shrapnel from the explosion (Equilibrium)

What is ideal fluid flow?

For idea fluid flow: -the fluid is incompressible (density is constant). This works well for liquids; gases are quite compressible. We can still use the Bernoulli equation for gases provided the pressure changes are small -there is negligible/little viscosity. Fluid is not too thick -the flow is laminar. Fluid is flowing smoothly. No turbulence. -the flow rate is steady. The value of f is constant *if these conditions are met, then total mechanical energy is conserved, and the Bernoulli equation may be used. **Bernoulli equation only applies to ideal fluid flow! *hydrodynamics (fluids)

For people with myopia, what correcting lens do they need?

For nearsighted pt's, they need a diverging/concave lens; light needs to be stretched to reach back of retina Eyeball is too long! (geometrical optics)

Forces acting ______ to the direction of travel always do zero work.

Forces acting perpendicular to the direction of travel always do zero work (Work)

What happens when a container of liquid water (holding 100mol of H2O) at 0C completely freezes? (note: ΔHfusion= 6kJ/mol and ΔHvap = 41kJ/mol) A)600 kJ of heat is absorbed B)600 kJ of heat is released C)400 kJ of heat is absorbed D)400 kJ of heat is released

Freezing means heat is released, we must use -ΔHfusion So, the heat of transition is q= (100mol)(-6 kJ/mol) → -600kJ (gas phase)

Which electrochemical cell type produces electricity from a spontaneous chemical reaction, an electrolytic cell or a galvanic cell?

Galvanic cells use spontaneous reactions to produce electricity, while electrolytic cells use electricity to force nonspontaneous reactions to occur

What volume of NH3 is made from 3L of N2 and 3L of H2 at STP? N2 (g) + 3H2 (g) → 2NH3 (g)

Gas stoichiometry can be done using volumes. If you are given the volumes of gases, you don't have to convert them to moles first, since volume is independent of the identity of the gas N2, (3L N2) (2NH3)/(1N2) → 6L NH3 H2, (3L H2)(2NH3)/(3H2) → 2L NH3, so H2 is the limiting reactant, and a total volume of 2L of NH3 can be made (gas phase)

What charge is generally associated with larger ions? with smaller ions?

Generally, negative ions are larger and positive ions are smaller (than a neutral atom)

element Au

Gold

Name the two parts of all electrochemical reactions, and define them based on electron transfer

Oxidation (loss of electrons) and reduction (gain of electrons)

Types of absorption spectroscopy:

IR spectroscopy UV/Vis spectroscopy NMR spectroscopy (molecular structure and absorption spectra)

What assumptions do we make about ideal gases?

Ideal gases are composed of molecules that take up no volume and experience no intermolecular forces

Of the following, which gas would likely deviate the most from ideal behavior at high pressure and low temperature? A)He(g) B)H2(g) C)O2(g) D)H2O(g)

Ideal gases have no volume and no intermolecular interactions. So, the one which will deviate the most from ideal behavior is water. Bc water experiences H-bonding, so it will feel stronger intermolecular forces than the other gases do. (gas phase)

State Newton's third law of motion

If object 1 exerts a force on object 2 ("action"), then object 2 exerts an equal but opposite force back on object 1 ("reaction")

What does it mean for light to be circularly polarized?

If two light waves of equal amplitude vibrate perpendicular to each other and have a 90° phase difference (the crest of one wave + the "x-axis=0" of the other wave), the light is circularly polarized. (this is how 3D glasses work when you go see a 3D movie). (geometrical optics)

Coulomb's constant:

In Coulomb's law, when using Felectrical = k |q1q2| /r², k is the proportionality constant, its value depends on the material between the particles. Usually particles are separated by empty space (air). So, k is often denoted as k₀ and called the COULOMB'S CONSTANT. Where k₀= 9x10⁹ Nᐧm²/C². *on the mcat, use this value of k unless specifically given another value (Electrostatics)

What is the sign of each electrode in a galvanic cell? In an electrolytic cell?

In a galvanic cell, the cathode is positive and the anode is negative. In an electrolytic cell, the electrode signs are reversed.

Positive charges want to move _______.

In the direction of the electric field, E (Electrostatics)

Negative charges want to move ________.

In the opposite direction of the electric field, E (Electrostatics)

Define torque and lever arm. Give two equations for calculating torque

Intuitively, torque is a quantity associated w a force, F, that measures the F's effectiveness at producing rotational acceleration. Lever arm, l, is the distance from the pivot point to the line of action of the force, so that the lever arm is perpendicular too F. Torque: 𝛕= rFsinθ or 𝛕=lF

Intuitively define viscosity. What is the relationship between the viscosity and density of a fluid?

Intuitively, viscosity is the internal friction of a fluid, caused by intermolecular forces. There is no connection between viscosity and density

The period and frequency are always:

Inversely related. Expressed by T=1/f (periodic motion)

Binding energy per nucleon is strongest for ____ and weakest for _____.

Iron (Fe-56, the most common isotope of Fe; has 26p+ and 30n; since a n is slightly more massive than a p+, need more binding energy to break up nucleus; Fe-56 has a very stable nucleus) Deuterium (hydrogen-2, has 1p+ and 1n) (atomic nucleus)

Deuterium, ²H, has how many neutrons?

It has 1p+ and 1n and 1e- (atomic nucleus)

Define kinetic energy. In what units is it measured? It is a vector or is it a scalar?

KE=the energy an object has by virtue of its motion=1/2mv², it is a scalar, measured in J

Give the equation for the maximum kinetic energy of an electron ejected as a result of the photoelectric effect. Define work function and stopping potential

KEmax=hf-work function The work function is the minimum energy needed to dislodge a surface e- from a metal. Stopping potential is the minimum voltage required to prevent ejected e-'s from reaching the detector

Units of density:

Kilogram per meter cubed, kg/m³ Symbol for density= ρ *mass/volume

Units of work:

Kilogram times meter squared per second squared, kgᐧm²/s² Note: kgᐧm²/s² = J = Nᐧm 1N= kgᐧm/s²

Describe the work done by kinetic friction:

Kinetic friction does negative work. Friction always acts against motion. (Work)

The speed of a transverse wave traveling along a certain 4-meter long rope is 24m/s. Which of the following frequencies could cause a standing wave to form on this rope, assuming both ends of the ope are fixed? A) 32 Hz B) 33 Hz C) 34 Hz D) 35 Hz

L=4m v=24m/s n=? f=? first, find the fundamental frequency: f1=nv/2L → f1=(1)(24)/(2)(4) →f1=3Hz All harmonic frequencies are whole-number multiples of the fundamental frequency. So a frequency that will cause a standing wave will be a multiple of 3Hz. Here, the only multiple is 33Hz. Answer=B

Sound is a _____ wave.

LONGITUDINAL WAVE. (sound)

State the Law of Reflection and the Law of Refraction (snell's law)

Law of reflection: angle of incidence=angle of reflection, θ₁=θ₁' Law of refraction: n₁sinθ₁=n₂sinθ₂

element Pb

Lead

How does a rocket relate to Newton's three laws of motion?

Like all objects, rockets are governed by Newton's Laws of Motion. The First Law describes how an object acts when no force is acting upon it. So, rockets stay still until a force is applied to move them. Likewise, once they're in motion, they won't stop until a force is applied. Newton's Second Law tells us that the more mass an object has, the more force is needed to move it. A larger rocket will need stronger forces (eg. more fuel) to make it accelerate. Newton's Third Law states that "every action has an equal and opposite reaction". In a rocket, burning fuel creates a push on the front of the rocket pushing it forward. This creates an equal and opposite push on the exhaust gas backwards. This causes the rocket to be launched. (Force)

Solute particles in solution like to keep the solution in a ____ phase.

Liquid phase. This is why it makes it harder to boil (bp increases) and also makes it harder to freeze (lowers the fp). Lowering the vapor pressure is just another fancy name for raising the bp (gas phase)

Both ___ and ____ are fluids.

Liquids and Gases (fluids)

What factors affect the period and frequency of a spring?

MASS and SPRING CONSTANT. Not amplitude. *if you increase the mass of the block on the spring, T will increase, while f will decrease *if you decrease the spring constant (get a spring that's very loose), T will increase, while f will decrease *if you decrease the mass of the block on the spring, T will decrease, while f will increase *if you increase the spring constant (get a tight spring), T will decrease, while f will increase (periodic motion)

Give the equation for the magnetic force exerted on a charge. What is the direction of this force?

Magnitude of force: F=|q|vBsinθ. F is perpendicular to v and B, obeying right-hand rule

Define mechanical advantage. In what units is it measured? Define efficiency.

Mechanical advantage is a measure of how much less force is required to lift a mass using a simple machine like a ramp or pulley system vs lifting it w/out the machine. MA=resistance force/effort force (in other words, force with no machine/force with machine), no units. Efficiency is the ratio of work output by a real-world machine to the energy input, and takes into account the thermodynamic fact that real machines lose energy to their environment bc of frictional effects

Units of area:

Meter squared, m^2

Units of length:

Meter, m

Are electromagnetic waves mechanical waves?

No! Electromagnetic waves do not need a medium to travel through. This is bc electric and magnetic fields oscillate rather than physical matter. So, EM waves can travel through empty space (vacuum). When EM waves travel through a vacuum, its speed is constant. This is the speed of light, c=3x10⁸ m/s *remember, mechanical waves (sound waves or waves on a string) need a medium to move through. (geometrical optics)

NMR vs MRI:

NMR generates information (a spectrum of light corresponding to chemical structure) based on the FREQUENCY OF EMITTED RADIATION. MRI instead generates information (images of the body) using the INTENSITY OF RADIATION (the quantity of re-emitted photons) arriving from various parts of body. Protons in dense or solid structures tend to be more or less prone to misalignment when the disrupting radio waves are applied to the body's tissue, resulting in a lower number of re-emitted photons coming from that region and thus a darker area in the resulting image. (molecular structure and absorption spectra)

Isotopes differ by the number of which fundamental particle? The mass number of an element is determined by which two particles?

Neutrons! Mass number= p+ + n

Units of force:

Newton, N *note: N=kgᐧm/s² A newton is equal to the force that would give a mass of one kilogram an acceleration of one meter per second per second F=ma, N=kgᐧm/s²

Black light is:

No colors of the visible spectrum are getting reflected off the object. The object absorbs all visible light. (geometrical optics)

Hydraulics:

On a hydraulic jack, consisting of two pistons with area, A, resting above two cylindrical vessels of fluid, Pascal's Law tells us that F1/A1=F2/A2. -the pressure input at one end is the same as the pressure output at the other. For ex, if you apply a force, F1 to a piston with area A1, this introduces a pressure change which will be transmitted through the fluid to the other end, without loss of magnitude. -the output force, F2, is greater than your input force, F1. This is why hydraulic jacks are useful! We end up lifting something very heavy (like a car) by exerting a much smaller force. -this comes at a price - since you are applying a small force over a small area, F1/A1, and getting a large force over a large area, F2/A2, there is a difference in distance, d, that the piston moves. A₁d₁=A₂d₂. You must exert F1 over a longer distance. F2 is exerted over a much shorter distance. The decrease in d is the same at the increase in F. For ex, if A2 is five times larger than A1, then F2 will be five times greater than F1, but d2 will only be ⅕ of d1 -the work done on one end is tha same as the work output at the other. Recall that W=Fdcosθ → W=Fd. Both ends of the piston are doing the same amount of work. In the pic, the left end has a smaller force and a larger displacement. While the right end has a larger force and a smaller displacement (fluids)

The electromagnetic force is _____.

One of the fundamental forces of nature! Strong force > electromagnetic force > weak force > gravity *The electromagnetic force is about one order of magnitude weaker than the strong force, but it can act at observable distances. Includes electric and magnetic effects, such as repulsion between like electrical charges or the interaction of bar magnets. It can be attractive or repulsive. Binds atoms together; Allows magnets to stick to your fridge; It is responsible for the fact that you are not falling through your chair right now. (Magnetism)

Gay-Lussac's Law:

P is directly proportional to T (constant n, V) P ∝ T or P1/T1 = P2/T2 CONSTANT VOLUME (gas phase)

Boyle's Law:

P is inversely related to V (constant n and T) P ∝ 1/V or P1V1 = P2V2 CONSTANT TEMPERATURE (gas phase)

Lens power:

P=1/f, where f is the focal length in meters; units of power is the diopter, D *a lens w a short focal length refracts light more (through larger angles) than a lens w a longer focal length. Thus, the lens w a short focal length has a greater power than a lens w a longer focal length. *since diverging lens have a -f, the power of diverging lens is - nearsighted, myopia, corrective lenses are diverging (eye too long) and have a negative power For ex, my glasses are -2.5 prescription *since converging lens have a +f, the power of converging lens is + farsighted, hyperopia, corrective lenses are converging (eye too short) and have a positive power For ex, my moms glasses are +3 prescription (geometrical optics)

What is the power dissipated by an 8Ω resistor w a current of 5A?

P=I²R → P= (5A)²(8Ω) → 200W (Circuit Elements)

Define gravitational potential energy. When does it change? Give a formula for the change.

PEgrav is the stored energy an object has by virtue of its position in a gravitational force field. It changes when the object's distance from the source of the gravitational field changes. ∆PEgrav=mg∆h

A 7kg ball is dropped from 20m. If the speed just before it hits the ground is 18m/s, what is the work done by air resistance?

PE₀ + Wnonconservative = KEf → mgh + Wnonconservative = ½ mv² → (7)(10)(20) + Wnonconservative = ½ (7)(18²) → Wnonconservative = -266 J (energy of point object systems)

What is the volume of 0.25mol He at 25C and 725 torr? (R= 0.08Lᐧatm/Kᐧmol)

PV=nRT n=.25 T=25C → If temp is -50C to +50C, close enough to STP (0C), can still treat as an ideal gas. P=725 torr → if pressure is 0.75 to 1.25atm, close enough to STP (1atm), can still treat as an ideal gas. *760torr=1atm, so (1atm/760torr)(725torr) → 0.95 atm **Here, since everything in in STP (or close enough), we can use 22.4L/mol for conversions (22.4L/mol)(.25mol) → 5.6L =V (gas phase)

Absolute pressure or total pressure of an object submerged in a liquid:

Ptotal= Patm + Pgauge Unlike gauge pressure, the total pressure is not proportional to either depth or density. (fluids)

How much energy is required to convert 20g of 90℃ water to 100℃ steam? Given: c of H2O(l) = 4 J/gK Given: ΔHvap (H2O) = 40kJ/mol

Question is asking for the energy just before and during the phase change, going from liquid→ gas. *For a phase change: q=nΔH → q=(1mol)(40kJ/mol) → q= 40kJ *Just before the phase change: q=mcΔT → q= (20g)(4J/gK)(10) → q=800J → 0.8kJ *total energy required is therefore: q=0.8+40 → 40.8kJ NOTE: Here, we see that q=mcΔT is very small (0.8kJ), this is normal! Bc of this, to save time, it is better to just calculate the phase change (only use q=nΔH), then look at answers and see what comes out the closest (gas phase)

When the potential difference between the ends of a wire is 12V, the current is measured to be 0.06A. What's the resistance of the wire?

R=V/I → R=12V/0.06A → 200 Ω (Circuit Elements)

If a certain blue photon excites an e- from n=2 to n=4, then which type of photon is needed to excite an e- from n=2 to n=3? A)X-ray B)UV C)violet D)red

RED (atomic nucleus)

Rank the colors of visible light in order from lowest frequency to highest

ROYGBIV

Define center of curvature, radius of curvature, focal point, focal length, concave, convex, converging, and diverging. How do the terms concave and convex relate to converging and diverging for lenses?

Radius of curvature=r=distance from center of curvature to mirror or lens Focal point (focus)=point where incident parallel rays of light reflecting off a mirror (or refracting through a lens) would focus (or, for convex mirrors and diverging lenses, the point from which incident parallel rays appear to diverge after striking mirror or passing through lens) Focal length, f=distance from focal point to mirror or lens, f=1/2r Concave mirror=spherical mirror w real focus, shiny surface curved toward the object (if you complete circle, it would enclose the object) Convex mirror=spherical mirror w virtual focus, shiny surface curved away from object (if you completed circle, it would not enclose the object) Converging lens=lens w real focus, thicker in middle than near edges Converging lens=convex lens Diverging lens=lens w virtual focus, thinner in middle than near edges Diverging lens=concave lens

Define real image, virtual image, upright image, and inverted image. Are there any relationships among these?

Real image=image formed by actual convergence of light rays Virtual image=image from which light rays only appear to diverge Upright image= image w same orientation as object Inverted image= image w opposite orientation from object real images are always inverted virtual images are always upright

Concave mirrors can create ____ images

Real, inverted and virtual, erect images (geometrical optics)

Which has the highest fp A)CH4 B)H2O C)CH₃OH D)(CH₃)₂O

Remember, mp and fp mean the same thing!! Here, looking for the most IMF's. CH4 only has LDF H2O has H-bonding CH₃OH has H-bonding (CH₃)₂O has dipole-dipole So, H-bond > dipole-dipole > LDF *H-bonding in H2O is always stronger than H-bonding in anything else (has 2 donors and 2 acceptors) **H2O has the highest fp and mp, strongest IMF's (gas phase)

Define resistance. In what units is it measured? Intuitively define resistivity. What is the relationship between resistance and resistivity?

Resistance: R=V/I. Units are in Ω, where 1Ω= 1V/A. Resistivity is the intrinsic resistance of a substance, R=ρ L/A

Resistors in series always share the same ______. And resistors in parallel always share the same ______.

Resistors in series always share the same CURRENT. Resistors in parallel always share the same VOLTAGE DROP. The voltage drops across series resistors will be different, and the currents through parallel resistors will be different, if the resistors are different. (Circuit Elements)

Standing waves vibrate at _________.

Resonance frequencies *when an object is forced into resonance vibrations at one of its natural frequencies, it vibrates in a manner such that a standing wave pattern is formed within the object. (periodic motion)

Rutherford model vs Bohr model:

Rutherford model= electrons assume arbitrary orbitals Bohr model= electrons assume quantized orbits (atomic nucleus)

Diverging ray diagrams:

SUV: small, upright, virtual images (geometrical optics)

Satellites orbiting the earth are in ________.

Satellites orbiting the earth are in free fall Their centripetal acceleration equals the acceleration from earth's gravity (ac=g). Even though they are accelerating toward the earth, they never crash into the earth's surface bc the earth is round (the surface curves away from the satellite at the same rate the satellite falls) (translational motion)

Units of time:

Second, s

A block of mass m slides down a ramp of incline angle 60 degrees. If the coefficient of kinetic friction between the block and the surface of the ramp is 0.2, what's the block's acceleration down the ramp?

See pic

Shell, subshells, and orbitals:

Shell → Subshell → Orbital -a shell in an atom is comprised of one or more subshells. *For ex, the n=3 shell has s, p, and d subshells -each subshell higher than s has multiple orbital orientations: x, y, z *s has 1 orbital *p has 3 orbitals *d has 5 orbitals *f has 7 orbitals **each orbital orientation is degenerate (has the same energy) **each orbital can hold up to two e- **each e- can be spin up or spin down (atomic nucleus)

Moving around a circle at constant speed, called uniform circular motion, is also _____.

Simple harmonic motion. -any motion that regularly repeats is referred to as periodic or harmonic motion. Includes uniform circular motion, a mass oscillating on a spring, and a pendulum -period= time it takes to move around the entire circle, (one revolution) second's/1rev -frequency= how many times the object goes around the circle in one second revolution's/1sec (Force)

Mechanical advantage:

Simple machines are tools that allow us to accomplish tasks w less applied force. Includes planes, pulleys, lever arms, screws, wheel and axle systems, etc. Through applying little input force (effort), you get a large output force -Mechanical advantage (MA) = resistance force/effort force = Fresistance/Feffort, where resistance force is the force that would be applied if no machine were being used, and effort force is the force applied w the machine -If the simple machine is used in the "idea word" where there are only conservative forces (no loss of energy due friction, heat, etc), the work done to complete the task using the machine is equal to the work done that would be required to complete the task w/out the machine. *the difference is that w less applied force, a larger distance must be covered to satisfy the work requirements (energy of point object systems)

An automobile w a certain shape experiences a drag force due to air resistance that is, in Newtons, equal to one-third the square of the car's speed, in meters pers second. How much power, in kilowatts, would the engine have to supply to the wheels to balance this drag force when the car is moving at a constant speed of 30m/s?

So, Fdrag=1/3v², Fdrag=1/3(30^2) --> Fdrag=300N We know that P=W/t → P= Fdcosθ/t → P=Fd/t → P=Fv *note, displacement/time is the same as velocity Now, P=Fv → P=(300)(v) → P=(300)(30) → 9000W or 9kW (energy of point object systems)

A vessel contains a mixture of three gases: A. B, C. There is twice as much A as B and half as much C as A. If the total pressure if 300 torr, what is the partial pressure of gas C? A)60 torr B)75 torr C)100 torr D)120 torr

So, the amounts of B and C are the same, and each is half the amount of A. Since this is a multiple choice question, instead of doing algebra, just plug in the choices and find the one that works. The only one that works is choice B, so Pa=150 torr, Pb=75 torr and Pc=75 torr, for a total of 300 torr (gas phase)

States of matter w highest intermolecular forces vs those w lowest/no intermolecular forces:

Solid > Liquid > Gas > Ideal gas *in order from highest intermolecular forces to lowest/no intermolecular forces

What is usually the densest phase of matter?

Solid, the main exception being water, which is most dense in its liquid phase

What usually happens to the solubility of solids in liquids as the temperature is increased? Why does this happen?

Solubility increases at higher temperatures bc solute-solute intermolecular forces weaken as solute molecules spread out due to increased vibration

Name at least three properties of liquids that depend on intermolecular forces

Solubility, vapor pressure, bp, mp, viscosity, surface tension

Describe at the molecular level what happens to a solid when it dissolves.

Solute particles are separated and encapsulated by solvent molecules such that the solute is observed to dissolve

If you see a dot symbol, what does that mean?

Something is coming out of the plane of the page (Magnetism)

If you see a x symbol, what does that mean?

Something is going into the place of the page (Magnetism)

Define quantized

Something is quantized if it only comes in certain discrete sizes

What is the acceleration of an object at terminal velocity?

Terminal velocity means vy is constant. If vy is constant, then a=0 (translational motion)

Three blocks hang below a massless meter stick. Block m₁ hangs from the 20cm mark, block m₂ hangs from the 70cm mark, and block m₃ hangs from the 80cm mark. If m₁=2kg, m₂=5kg, and m₃=3kg, at what mark on the meter stick should a string be attached so that this system would hang horizontally?

The 1st step is to choose an origin or reference point to call x=0. Since the question is essentially asking how far from the L end of the meter stick should we attach the string, it makes sense to choose our zero mark at the L end. x₁=20cm, x₂=70cm, x₃=80cm (2kg)(20cm) + (5kg)(70cm) + (3kg)(80cm) // 2kg + 5kg + 3kg → 63cm *note: 63cm = .63m = .00063km (Force)

Overall, as the temperature of a gas sample decreases, what happens?

The KE decreases, average speed of the gas particles decrease, pressure on the side of the container decreases. Why if you have an open water bottle at room temp, then you put it in fridge, the container shrinks/shrivels up. There is less pressure being exerted on the sides of the container. (gas phase)

Overall, as the temperature of a gas sample increases, what happens?

The KE increases, average speed of the gas particles increases, pressure on the side of the container increases. (gas phase)

If something is moving at a constant speed, either:

The a=0 or the acceleration is perpendicular to the velocity (translational motion)

The Big Five are only used in situations where _______.

The acceleration is constant (translational motion)

If an object moves in a circle w non constant speed, what must be true about its acceleration?

The acceleration would have a tangential component (this changes the speed) in addition to its radial (or centripetal) component (which just keeps it in circular motion)

Heat capacity and Specific heat:

The amount of heat absorbed or released by a sample (which is NOT undergoing a phase transition) is proportional to its change in temp. -Every substance has a "heat capacity" or "calorimeter constant," C, which is just the substances "specific heat," c, times its mass, m. So, C=mc *for a substance not undergoing a phase transition, its temp changes. *This can be expressed by: q=mcΔT, where q is the heat added (or released by) a sample, m is the mass of the sample in grams, c is the specific heat of the substance, and ΔT is the temp change (note: here temp can be in celsius or K or whatever... You are just looking for the change in temp) *can also be written as: q=CΔT, where C is just (c)(mass) In summary, c = specific heat. Units are J/g℃ = J/gK C = mc = heat capacity or calorimeter constant. Units are J/℃ = J/K *specific heat, c, is a proportionality constant that defines how much heat must be added to or removed in order to change the temp of a sample by 1℃ or 1K *heat capacity measures the amount of heat required to change a substance's temperature by a given amount

Why is the mass of a nucleus not equal to the mass of the individual protons and neutrons that comprise it?

The binding energy that is released when the nucleons are bound together in the nucleus comes from the mass defect according to E=mc²

Bohr model of the HYDROGEN atom:

The bohr model of the H atom is useful bc it allows you to determine ionization energies. *during absorption, the electron transitions to a higher energy level, moving from the n=1 shell to a higher level energy shell (n=2, n=3, etc). The energy of each energy level is governed by: En= -13.6eV/n², where En is energy associated with a certain shell, and n is the shell (n=1,2,3, etc). -the more negative (lower) the energy, the more stable the orbit, the harder it is to knock out the electron (for ex, the n=1 shell has E=-13.6eV) -the less negative (higher) the energy, the less stable the orbit, the easier it is to knock out the electron (for ex, the n=3 shell has E=-1.5eV) *as n approaches infinity, En approaches 0. In other words, as the e- gets infinitely farther away from the nucleus, the binding energy becomes 0eV (no electrostatic attraction). The atom is ionized For ex, the energy associated with an electron in the n=2 shell for hydrogen is, E=-13.6eV/2² → -3.4eV. Or, the energy associated with an electron in the n=3 shell for hydrogen is E=-13.6eV/3² → -1.5eV. As the electron moves farther away from the nucleus, (the n=1, n=2, n=3, shell), the electron's energy increases (gets closer to zero; it becomes less negative). This makes it easier for an atom to become ionized. **You can calculate the ionization energy (energy which must be absorbed to remove an electron) by looking at ΔE (see pic) (atomic nucleus)

Using a phase diagram, what can be found along the liquid-gas phase boundary?

The bp and condensation point are the same, and both can be found along the liquid-gas boundary

Electric field vector vs electric field line vs force at point P:

The electric field vector at any point is always tangent to the field line passing through that point, and its direction is the same as that of the field line. The force a certain object, P, feels can be in the same direction or opposite of the electric field (Electrostatics)

Electromagnetic spectrum:

The electromagnetic spectrum consists of electromagnetic waves of varying wavelength. *lower frequency, longer wavelength, less energy* -Radio: causes electronic oscillations in an antenna -Microwave: causes molecular rotation -Infrared, IR: causes molecular vibrations -Visible, ROYGBIV: can excite electrons to orbits of higher energy. Visible light ranges from wavelengths of 400-700 nm. 700ish being red, and 400ish being violet -Ultraviolet, UV: can break bonds and excite electrons so much as to eject them, which is why UV is considered ionizing radiation -X-rays: ionizing radiation, photoelectric effect -Gamma rays: even more energetic than x-rays *higher frequency, shorter wavelength, more energy* Note: microwaves (the radiation that's used to cook food in a microwave), infrared waves (the radiated heat you feel from a stove), ultraviolet waves (the radiation that causes sunburns) Acronym to remember: R-Roman M-Men I-Invented V-Very U-Unusual X-ray-X-ray G-Guns (geometrical optics)

What is the relationship between the electric field and the electric force?

The force F on a charge q located at a position where the electric field is E is given by F=qE

If you push a crate resting on the floor w insufficient horizontal force to make it move, is the static friction force more than, equal to, or less than the pushing force?

The force of static friction will be equal to the pushing force, since the crate remains motionless. Ffstaticmax=µFn will be greater than or equal to the pushing force

If a charged particle's velocity, v, is parallel to the magnetic field lines, B, what happens?

The force of the magnetic field= zero. So, a charge can be moving through a magnetic field and yet feel no force if its direction of motion is parallel to the magnetic field lines. (Magnetism)

Using a phase diagram, what can be found along the solid-liquid phase boundary?

The fp and mp are the same, and both can be found along the solid-liquid phase boundary

What structural information does an infrared spectrum show?

The functional groups present in the molecule

Half-life:

The half-life, denoted by t1/2, is the time it takes for half of a sample to decay *After 1 half-life, the amount of the original stuff decreases by half. *After 2 half-lives, the amount of the original stuff decreases by a factor of 4. *After 3 half-lives, the amount of the original stuff decreases by a factor of 8. *After 4 half-lives, the amount of the original stuff decreased by a factor of 16 1→1/2 1/2→1/4 1/4→1/8 1/8→1/16 *shorter the half-life, the faster the decay *can also relate half-life to the decay constant, k. The decay constant is inversely proportional to the half-life (atomic nucleus)

Volume, temp, and pressure of an ideal gas are related by a simple equation called _____.

The ideal gas law! PV=nRT *pressure in atm *volume in L *R, gas constant is 0.08 Lᐧatm/Kᐧ mol *temperature in kelvin (gas phase)

What is a mercury barometer?

The mercury barometer measures atmospheric pressure by allowing the atmospheric pressure to "push" on a column of mercury. -the barometer is open at one end and closed off (vacuum) at the other end -the atmosphere "pushes" at the open end, which results in the mercury rising up in the closed end -this measures atmospheric pressure, P=F/A, where F is the weight of the mercury that got pushed up and A is the cross-sectional area of the column that the mercury got pushed through -standard mercury barometers are calibrated such that 1atm of pressure will push the mercury up by 760mm. For convenience, mm Hg is also called the torr. 1 atm = 760 torr = 760 mmHg = 101 kPa = 101,000 Pa *note: pressure decreases at higher elevations; pressure increases at lower elevations (gas phase)

What does the splitting in a ¹H NMR spectrum indicate? What does the number of signals in the spectrum show?

The number of nonequivalent hydrogens on the adjacent carbon atoms; the number of nonequivalent hydrogens in the molecule

Stoichiometric coefficients:

The numbers which proceed each compound, ex 2Al + 6HCl → 2AlCl3 + 3H2, here the stoichiometric coefficients are 2, 6, 2, and 3 *an equation w coefficients is a balanced equation

What does a positive reduction potential indicate?

The reduction half-reaction is spontaneous, while the associated oxidation half-reaction (the reverse reaction) is nonspontaneous

The position (x) vs time (t) graph:

The slope of the position vs time graph gives the velocity (translational motion)

The velocity (v) vs time (t) graph:

The slope of the velocity vs time graph gives the acceleration *on the graph, if there's no change in velocity (straight line going across), the slope is 0, and the acceleration is zero. The area under the velocity vs time graph gives the displacement (translational motion)

How does the solubility of gases in liquids depend upon temperature and pressure?

The solubility of gases decreases w increasing temperature, but increases w increasing pressure

A transverse wave of frequency 4Hz travels at a speed of 6m/s along a rope. What would be the speed of a 12Hz wave along this same rope?

The speed of a wave is determined by the type of wave and the characteristics of the medium, not by frequency. Thus, the wave speed will still be 6m/s. Frequency does not affect the wave speed (periodic motion)

Spectroscopy:

The study of the interaction between electromagnetic radiation and matter. It is a fundamental exploratory tool in the fields of science, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic scale, molecular scale, macro scale, etc, by using electromagnetic waves. Spectroscopy can be classified by the nature of the interaction between the energy and the material. These interactions include: -absorption -emission -resonance spectroscopy *remember, when an electron gets excited from its ground state, it must lose the energy it gained. It does this by the emission of heat, or less commonly, light. (molecular structure and absorption spectra)

Why do helium-filled balloons rise whereas an air filled balloon sinks?

There is more force down on an air filled balloon than on a helium filled balloon (Fw on the air balloon > Fw on the helium balloon). The Fbuoyancy is the same on both balloons. (fluids)

Put the vessels of the cardiovascular system in order by diameter:

Thickness: artery > vein > arteriole > venule > capillary (circulatory system)

element Sn

Tin

Law of refraction:

To find the angle of refraction, use Snell's Law: n₁sinθ₁ = n₂sinθ₂, where n is the refractive index and θ is the angle to the normal *when light moves to a denser medium (higher refractive index, n), it bends toward the normal. For ex, when light moves from air to water. n₂>n₁ and θ₂<θ₁ *when light moves to a less dense medium (lower refractive index, n), it bends away from the normal. For ex, when light moves from water to air. n₂<n₁ and θ₂>θ₁ (geometrical optics)

A substance is analyzed and consists, by mass, of 70% iron and 30% oxygen. Find the empirical formula for this compound.

To find the empirical formula for this compound, the trick is to start w 100g of the substance. We choose 100g since percentages are based on parts in 100. 100g of this substance would then contain 70g of Fe and 30g of O. Now, find the moles of Fe and O present in this substance: Moles of Fe = (70g Fe)(1mol/56g) → 5/4 Moles of O = (30g O)(1mol/16g) → 15/8 *ration of Fe to O = 5/4 // 15/8 → (5/4)(8/15) → ⅔ So, the ratio of Fe to O is 2:3, the empirical formula of the substance is Fe2O3

Find the mass of an object whose weight is 50N.

To find the object's mass, just divide its weight by g, so (50N)//(10N/kg) → 5kg (Force)

What is the purpose of the salt bridge in a galvanic cell?

To prevent charge separation as electrons move from one chamber to the other. The salt bridge maintains charge neutrality in each chamber

Explain the strong force and electromagnetic force in the nucleus

Two fundamental forces in the nucleus: 1) Strong force= also called the nuclear force. It binds nucleons together, and therefore contributes to the binding energy 2) Electromagnetic force= due to electrostatic repulsion between the positively charged protons in the nucleus *the nucleus stays together bc the strong force is much stronger than the electromagnetic repulsion *remember, there is a total of four universal fundamental forces: nuclear force/strong force EM force weak force gravitational force (atomic nucleus)

How does ultrasound involving pregnancies work?

Ultrasound imaging is based on the reflection property of sound. A source emits ultrasound, which reflects off a surface back into the detector to form an image. Ultrasound is sound that is too high in frequency for humans to hear. (sound)

What will happen to the capacitance of a parallel-plate capacitor if the plates were moved closer together, halving the distance between them?

Using C=ɛ A/d, we see that C is inversely proportional to d. Thus if d is decreased by a factor of 2, then C will increase by a factor of 2 (Circuit Elements)

A hole is opened at the bottom of a full barrel of liquid. When the efflux speed has decreased to ½ the initial efflux speed, the barrel is how full?

Using Torricelli's result, Vefflux = √2gD, we see that v ∝ √D. So, if v decreases by a factor of 2, then D has decreased by a factor of 4. So the answer is that the barrel is ¼ full. (fluids)

Light of wavelength 700 nm shines through a double slit whose holes are 200 nm wide and are spaced 1300 nm apart. If a screen is placed 3m away from the double slit, what will be the distance from the central bright spot on the screen to the next bright spot?

Using the double slit equation, dsinθ=mƛ → (1300nm)sinθ=1(700nm) → 700/1300 = sinθ → 7/13=sinθ → θ= 30 degrees *now to find d, tan(30)=Δy/3m → Δy=3tan(30) *tan is sin/cos, so tan(30) is ½ // √3/2 → (½)(2/√3) → 1/√3 *and, (3)(1/√3) → 3/√3 → ~ 2m is the distance (light/electromagnetic radiation)

State Ohm's Law

V=IR where R is independent of V (or I)

Source charges create both _______ and _________.

Vector fields and Scalar fields -the ELECTRIC FIELD due to a source charge can be viewed as a collection of vectors. This allows you to answer questions about vector quantities, like force and acceleration, using the equations F=qE and a=F/m = qE/m. *while the electric field has the same magnitude at every point a distance r from Q, the field has a different direction at every point on the circle, (or the sphere), of radius r centered on Q. Therefore, we're forced to say that the electric field isn't the same at every point a distance r from Q bc the directions are all different. *the electric field, E, is unitless -the ELECTRIC POTENTIAL due to a source charge can be viewed as a scalar field. This allows you to answer questions about scalar quantities, like energy, work, and speed, using the equations ɸ=k Q/r, *the electric potential is the same at every point that's a distance r from Q, (equipotentials) *electric potential, has units of volts, V, (a volt is just a joule per coulomb, J/C) (Electrostatics)

Describe the image formed in a plane mirror:

Virtual and erect (geometrical optics)

Convex mirrors can create ____ images

Virtual, erect images (geometrical optics)

A particular eucalyptus tree has a density of 667 kg/m³ and a mass of 6000kg. What volume of the tree would float above the surface of water?

Vsubmerged/Vobject = 𝝆object/𝝆fluid → Vsubmerged/Vobject = 600/1000 → Vsubmerged/Vobject = 6/10 → Vsubmerged/Vobject = ⅗ *so, ⅗ is submerged and ⅖ is above the water *And density, 𝝆 = m/V → 600=6000/V → V= 6000/600 → 10=V *So, ⅖ of the volume, 10, is: (⅖)(10) → 20/5 → 4m³ is the approximate volume of the tree that would float above the surface (fluids)

Units of power:

Watt, W

Find the weight of an object whose mass is 50kg.

Weight = mg, so weight=(50kg)(10N/kg) → 500N (Force)

What is a laser?

When doing double-slit interfere, a laser light must be used. If you used a regular light bulb instead, no interference pattern would be produced. This is bc light bulbs send light in all directions. With a laser, all waves are at a constant frequency (monochromatic) and have a constant phase difference (coherent). This allows an interference pattern to be produced. *so for waves to interfere consistently over time, two conditions must be met, (1) the waves must vibrate at the same constant frequency (called a monochromatic wave). And (2), the phases of the waves must be synchronized, meaning that as time passes they must arrive at a particular location consistently in phase, out of phase, or somewhere inbetween. The phase difference must remain constant in time (called coherent waves). (light/electromagnetic radiation)

Stability and decay:

When something is stable, it doesn't decay. When something is unstable, it decays. The more unstable something is, the shorter the half-life. (atomic nucleus)

When does a liquid boil?

When vapor pressure of the liquid = atmospheric pressure

Define a nonconservative force. Give an example. State an equation for conservation fo total energy in the presence of such forces.

Whereas the work by a conservative force like gravity depends only upon the initial and final positions of the displaced object, a nonconservative force does (negative) work according to the total distance traversed by an object. Kinetic friction is an example. In the presence of nonconservative forces, the Total mechanical energy is reduced by the negative work done by those forces: ∆KE+∆PE=Wnonconervative

____ and ____ are interchangeable.

Work and energy are interchangeable (energy of point object systems)

Is it possible for a moving object to experience a static friction force?

Yes! A tire, rolling without slipping. (Force)

Is it possible for a force acting over a distance to perform no work?

Yes, if the force is perpendicular to the direction of displacement.

Is it possible to have a net torque but no net force? Is it possible to have a net force but no net torque?

Yes. Something can have a net torque (may be spinning) but can have a zero net force (not translating; no linear motion) Something can have a net force (translating; moving linearly) but can have zero net torque (not spinning)

Does an object that is totally submerged feel a buoyant force?

Yes. Whenever an object (whether floating, suspended, sinking, or resting at bottom) is in contact w a fluid, there is a buoyant force

How do you know when to use phenolphthalein?

You choose indicators based off of the desired pH. If you want to know when something turns basic, you would use phenolphthalein, since it's pKa = 9. So, when you approach pH 9, your solution will slowly turn pink, until you eventually get a consistent light pink, the endpoint. The endpoint is when the equivalence point is reached, or when you have 100% A- (molecular structure and absorption spectra)

In mass spectrometry, what if the high energy electrons "miss" your molecule?

Your molecule is neither fragmented nor ionized. Uncharged molecules are not detected and are not included in the mass spectra. (molecular structure and absorption spectra)

Harmonic motion:

any motion that regularly repeats is referred to as periodic or harmonic motion. The motion can be described by a cosine or sine function. (periodic motion)

What is the e- configuration for copper metal?

[Ar]4s¹ 3d¹⁰ (electronic structure)

What is the e- configuration for chromium metal?

[Ar]4s¹3d⁵ (electronic structure)

Mole fraction:

a component (fraction) of a certain gas compared to the total number of moles of the entire gas mixture. Given by: Pa = (Xa)(Ptotal), where Xa= moles of a/total moles (gas phase)

How do you mathematically distinguish between concave and convex mirrors? Between converging and diverging lenses?

a concave mirror has f>0, but a convex mirror has f<0 a converging (convex) lens has f>0, but a diverging (concave) lens has f<0

Pascal's Law:

a confined liquid will transmit an externally applied pressure change to all parts of the fluid and the walls of the container without loss of magnitude. In other words, if you squeeze a container of fluid, the fluid will transmit your squeeze perfectly throughout the container. The most important part of Pascal's Law is hydraulics, which says: F1/A1 = F2/A2 (fluids)

If something increases by a factor of four, what does this mean?

a factor of " is used commonly to mean the same as "multiplied by" or "divided by." If x is INCREASED by a factor of 4, it becomes 4x. If x is DECREASED by a factor of 4, it becomes x/4. The key word is the direction of change (increased / decreased) by a factor of.

Mechanical waves vs electromagnetic waves:

a mechanical wave is a series of disturbances (oscillations) within a medium that transfers energy from one place to another. The medium itself is not transported, just the energy. Examples include a vibrating string or sound. Mechanical waves cannot exist w/out a medium (for ex, sounds waves cannot travel through a vacuum). Electromagnetic waves do not need a medium. This is bc electric and magnetic fields oscillate rather than physical matter. (periodic motion)

Mirror:

a mirror is a surface, usually made up of glass or metal, that forms an image of an object by reflecting light. Note: mirrors completely reflect light. The angle of incidence equals the angle of reflection. (geometrical optics)

Elastic collisions:

a perfectly elastic collision is one in which both momentum and total KE are conserved. So, total KE before = total KE after. Note: KE is scalar, so there are no positive/negative signs to worry about Examples of elastic collisions: -if you drop a ball and the ball bounces back to its original height, that's a perfectly elastic collision -if you throw a ball at a wall and your ball bounces back w exactly the same speed as it was before it hit the wall, that's a perfectly elastic collision (Equilibrium)

State Pascal's law

a pressure that is applied to the surface of a confined liquid is transmitted undiminished to every part of the liquid; all points at the same height have the same pressure

Elementary charge:

a proton carries a charge of +e and an electron carries a charge of -e. This "e" is called the elementary charge and is: e=1.6x10⁻¹⁹ Coulombs *in other words, one electron or one proton carries a charge of 1.6x10^-19 C. Example: The F- ion is -1 elementary unit, (-1e). The charge of a fluorine ion is -1.6x10⁻¹⁹ C. The Ca2+ ion is +2 elementary units (+2e). The charge of a calcium ion is +3.2x10⁻¹⁹ C (Electrostatics)

Resistors:

a resistor is a component in an electric circuit that has a specific resistance. Resistors in a circuit can either be in series or in parallel. (Circuit Elements)

What is a conjugated system?

a system of connected p orbitals with delocalized electrons in a molecule, which in general lowers the overall energy of the molecule and increases stability. It is conventionally represented as having alternating single and multiple bonds. (molecular structure and absorption spectra)

Chromatic aberrations:

a type of aberration where blue light gets refracted more than red light, so different color focus differently. It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. (geometrical optics)

Spherical aberrations:

a type of aberration where not all light will focus on the focal point (geometrical optics)

Ions of hydrogen:

can have H+, a hydrogen proton, or just called a proton, contains 1p+, 0n, 0e- *note: hydronium is H3O+ can have H-, a hydride ion, or just called an electron, contains 1p+, 0n, 2e- *note: hydroxide is OH-

Blood pressure is directly proportional to:

cardiac output and peripheral resistance (circulatory system)

There are two types of ions. Identify them by name and their type of charge

cations are positive anions are negative

What is the electric charge on a proton? an electron?

charge on proton= +e and charge on an electron= -e, where e=elementary charge= 1.6x10^-19 C

Unsaturated solution:

concentration < solubility, additional solute can still dissolve

Saturated solution:

concentration=solubility, no additional solute will dissolve

Semi-log plots:

converts exponential curves into straight lines *Something that curves up becomes a straight line with a positive slope. *Something that curves down becomes a straight line with a negative slope. *For exponential decay, a semi-log plot graphs the log of amount vs. time. *For exponential decay, a semi-log plot is a straight line with a negative slope. *The semi-log plot intercepts the x axis where the original y value is 1. (atomic nucleus)

A particle has an initial velocity of 10m/s and a constant acceleration of 3m/s² in the same direction. How far will the particle travel in 4 seconds?

d=v₀t + ½ at² → (10m/s)(4s) + ½ (3m/s²)(4s)² → 64m (translational motion)

Vasodilation:

decrease BP (circulatory system)

Colligative properties:

depend on the amount of solute particles but not on their identity. For ex, it doesn't matter if its NaCl of MgCl, either way both will have a van't hoff factor of i=2 (both dissociate into two ions). There are four colligative properties, these are: 1)fp 2)vapor pressure 3)bp 4)osmotic pressure Ex: one mole of sucrose (i=1) will have the same number of particles in solution as 0.5mol of NaCl (i=2), and therefore will have the same effect on a given colligative property When you add increasing amounts of solute: *fp depression (fp decreases) *vapor pressure depression (Pvap decreases) *bp elevation *osmotic pressure elevation (gas phase)

Effective nuclear charge _____ as you move in a row.

effective nuclear charge increases for outer electrons as you go across the periodic table, (left to right, in a row) *Felectrostatic also increases, (periodic table; group and row)

The elasticity of solids:

explains the relationship between the forces applied to a solid object and the resulting change in the object's shape (fluids)

Hydrostatics:

fluids at rest (fluids)

Hydrodynamics:

fluids, (liquids or gases), in motion (fluids)

What will happen to a wave's frequency, speed, and wavelength when it enters a new medium?

frequency remains unchanged; both v and λ will change, proportionally

What temperature and pressure conditions allow most gases to behave most ideally?

high temperatures and low pressures (or large volumes)

When a substance absorbs or releases heat energy, one of two things can happen:

its temp changes OR it undergoes a phase change BUT NOT BOTH AT THE SAME TIME.

Units of mass:

kilogram, Kg

Unpolarized light:

light w electric field oscillating in many planes. *most EM waves have electric fields oscillating in all perpendicular directions to propagation equally and are thus unpolarized (geometrical optics)

What is linear or translational motion?

linear/translational motion is non-rotational motion, vs rotational motion which is motion in a circle

State the mirror-lens equation and the magnification equation

mirror-lens equation: 1/o + 1/i = 1/f magnification: m=-i/o

Properties of melting or freezing point:

mp or fp is the temperature at which the fusion or crystallization phase transition occurs. 2 main properties: 1)external P is directly proportional to mp or fp, Patm∝mp or fp *if you increase the external pressure, you also increase the mp or fp 2)intermolecular forces are directly proportional to mp or fp, IMF∝mp or fp *more intermolecular forces=higher fp (it will freeze easier), and higher mp (harder to melt) (gas phase)

What is the sign of the cell voltage in an electrolytic cell?

negative

Give examples of non-ionizing radiation

non-ionizing radiation= EM radiation that is too low in energy or frequency to cause ionizing damage. Examples include: radio, microwave, IR *note: when a nucleus undergoes radioactive decay, the emission of an alpha particle, beta particle, positron, of gamma ray can all cause ionizing damage with atoms it comes in contact with

What does NMR stand for?

nuclear magnetic resonance because the nuclear stands for protons; magnetic stands for the external magnetic field; the resonance stands for the absorption of radio waves. (molecular structure and absorption spectra)

When talking about spontaneous fission, what is a chain reaction?

one atomic nuclei is splitting apart. Ex, Uranium undergoes fission when struck by a free neutron. The fission of uranium generates more neutrons, which goes on to split other Uranium nuclei. This is called a chain reaction (atomic nucleus)

Optically active molecules either rotate polarized light ____________.

optically active molecules either rotate polarized light clockwise or counterclockwise (geometrical optics)

Cesium-137 has a half-life of 30 years. How long will it take for only 0.3g to remain from a sample that had an original mass of 2.4g?

original mass= 2.4g current mass= 0.3g 1 half life, 2.4→1.2 2 half life, 1.2→.6 3 half life, .6→.3 So, 3 half-life have passed (3)(30) = 90 Answer: 90 years

In an oxidation-reduction reaction, the oxidation number of an aluminum atom changes from 0 to +3. The aluminum atom has been:

oxidized, and is a reducing agent (electrochemistry)

Double bonds occur bc of the overlap of _______.

p orbitals from two atoms (molecular structure and absorption spectra)

What does it mean for resistors to be in parallel? What is true about the voltage drops across such resistors? The currents?

parallel= resistors side by side giving alternative paths for current. Parallel resistors must share the same V. I's may be different and must add up to the total I supplied by the power source

Explain the difference between paramagnetic and diamagnetic elements, and give an example of each

paramagnetic elements have unpaired electrons (like N) and diamagnetic elements have all their electrons paired (like Ne, or any element w a filled orbital shell)

Crests:

peaks/high points of a wave. The distance between one crest to the next gives you the wavelength. (periodic motion)

Power:

power is the rate of work, or how fast work gets done. Power can also be thought of at the rate of energy use. A larger power means more work is getting done in a shorter amount of time. Lifting a crate in one minute requires more power than lifting the same crate in an hour. It is expressed by: P=W/t, power=work/time -the unit for power is the watt, W. 1W = 1J/s = energy/time -note: P = W/t = Fd/t = Fv (Work)

Force of gravity for fluids:

previously, when talking about weight, we said Fg=mg. However, w fluids it is difficult to remove a portion of fluid from a tank, place it on the scale and find its mass. So, the Fg for fluids is expressed by: Fg = 𝝆Vg, where 𝝆 is density, V is volume and g is gravity *this equation came from the fact that Fg=mg and 𝝆=m/V → m=𝝆V. Plugging this into the Fg equation gives us the above equation (fluids)

What type of mathematical relationship is associated with all radioactive decay?

radioactive elements decay exponentially w respect to time

Velocity:

rate of change in displacement; vector, has direction. Can be described by: average velocity = displacement/Δt. Note: average velocity is written w a bar over v -instantaneous velocity= velocity and direction at an instant (infinitesimal time interval). -the direction of instantaneous velocity is tangent to the path at that point. -instantaneous speed equals instantaneous velocity in magnitude -you can have a positive or negative velocity -velocity always points in the same direction as displacement -units are in m/s Ex, a sprinter runs around a circular track of radius 100m. This takes 2min for her to complete one lap. What is the runner's average velocity? Avg velocity=displacement/Δt → 0/120s → 0 is her avg velocity (translational motion)

Reduction and oxidation in terms of electrons, hydrogen, and oxygen:

reduction= gain of e-, gain of H, loss of oxygen oxidation= loss of e-, loss of H, gain of oxygen

Equipotential lines:

regions in space where the potential is the same. Equipotential lines are always perpendicular to the electric field lines (Electrostatics)

Resistance:

resisting the flow of charge. Expressed by: R=V/I, where V is the voltage and I is the current. *resistance has units of ohm, (Ω). Volts per Amp *for a given voltage, resistance and current are inversely proportional **a large current, I, results in a small resistance **a small current, I, results in a large resistance (Circuit Elements)

Isotope:

same element (same number of p+), just diff number of neutrons Ex, carbon-12 vs carbon-13 *Can also be written as ¹²C or ¹³C Isotopes often have similar chemical properties, but different stabilities (some decay and give off radiation, some don't) (atomic nucleus)

What are the phases of matter?

solid, liquid, gas

Buoyant force:

the force exerted up on an object either partially or completely submerged in a fluid or gas due to the pressure difference between the top and bottom of the object -Archimedes' principle= the magnitude of the buoyant force is equal to the weight of the fluid displaced by the object. Expressed by: Fbuoyancy= weight displaced= (mass displaced)(g)= (⍴fluid)(Vsubmerged)(g) -things will rise upward when Fbuoyance > object weight -things will sink when Fbuoyancy < object weight -things float when Fbuoyancy = object weight (fluids)

A crate that weighs 1000N rests on a horizontal floor. The coefficient of static friction between the crate and the floor is 0.4. If you push on the crate w a force of 250N, what is the magnitude of the force of static friction?

the maximum force of static friction that the floor could exert on the crate is Ffs,max = µsFn → (.4)(1000) → 400N. However, if you exert a force of only 250N on the crate, then static friction will only be 250N. Just imagine what would happen to the crate if you pushed on it w a force of 250N and the floor pushed it back toward you w a force of 400N! (Force)

If a pulley is massless and frictionless, what is true about the the tension in the cord on both sides of the pulley?

the tension is the same on both sides of the pulley

What are the common labels for the curve of a redox titration?

the y-axis is normally E, electric potential in volts and the x-axis is normally the amount of titrant added in mL of solution

The significance of Newton's 1st law on equilibrium is:

things in equilibrium will remain in equilibrium unless acted on by an external force. Force makes things accelerate; change velocity or change direction. (Equilibrium)

The significance of Newton's 1st law on momentum is:

things resist change in momentum bc of inertia. Try stopping a truck. It's not easy bc it resists changes to its huge momentum. Momentum is expressed by: p=mv (Equilibrium)

In mass spectrometry, what if the high energy electrons do not break apart your molecule, but merely ionizes it?

this "molecular ion" will be detected as the parent peak, also called the molecular ion peak. (molecular structure and absorption spectra)

Potential due to an electric dipole:

to calculate the exact potential at a given point, just calculate the individual potential due to the positive charge and the negative charge, then add them together (Electrostatics)

Resistors in parallel:

two resistors are said to be in parallel if they provide alternative routes from one point in a circuit to another. All resistors in parallel share the same VOLTAGE, V. *to get the total resistance for resistors in parallel, Rtotal = R1R2 / R1 + R2, you can only do two resistors at a time *notice that the Rtotal is always less than the smallest resistance in the combination (Circuit Elements)

Resistors in series:

two resistors are said to be in series if each follows the other along a single connection in a circuit. All resistors in a series share the same CURRENT, I. *to get the total resistance for resistors in series, just add the resistances Rtotal= R1 + R2 + .... *notice that the Rtotal is always greater than the largest resistance in the combination (Circuit Elements)

Spontaneous fusion:

type of radioactive decay in which two atomic nuclei fuse together. Ex, hydrogen and hydrogen can fuse to form helium. The sun works by fusion. Hydrogen in the sun fuses to form helium. (atomic nucleus)

X-ray diffraction:

used to examine the structure of crystals. Something is called a "crystal" if the atoms or molecules that make up the substance are arranged in a regular, periodic way; arranged in a lattice. When an x-ray hits an object that is made up of equally spaced atoms, some of the wave will be reflected, and some will enter the object and undergo refraction. At each atom inside the object, some x-ray's will be reflected and some will be refracted. *Summary: X-ray diffraction = X-rays diffracting (hitting) on a crystal. Patterns of interference that results from this is used to deduce the structure of the molecules in the crystal. *This is how Watson and Crick discovered the double helical shape of DNA. (light/electromagnetic radiation)

Right hand rule:

used to predict the direction of the magnetic force. -Point thumb in the direction of v -Point Fingers in the direction of the magnetic Field, B -Palm gives the direction of F for a positive charge -Back of hand gives direction of F for a negative charge F is always perpendicular to both v and B (Magnetism)

An object is dropped from a height of 80m. How long will it take to strike the ground?

v₀= 0 vf= ? a= 10m/s² (the object's initial displacement is down, so used +gravity value) d= 80m t= what we want d=v₀t + ½ at² → d= 0 + ½ at² → t= √(2d/a)→ t=4s (translational motion)

How do you get an atoms emissions spectrum?

when a gas is energized, the gas glows with a particular color. If that light is passed through a prism, then dispersion will cause the light to separate into its component colors, corresponding to frequencies and wavelengths. This pattern of distinct bright lines of color is called the element's emission spectrum (atomic nucleus)

Poiseuille flow:

when a viscous fluid flows through a pipe, the flow has a front that is shaped like a parabola bulging outward *hydrodynamics (fluids)

Static equilibrium:

when something is in static equilibrium, its acceleration=0, its velocity=0. Thus, Fnet=0 and net torque=0. It is sitting still and not moving. (Equilibrium)

Dispersion:

when visible light passes from one medium to another, some wavelengths are bent more than others (have diff refracted rays). This is bc waves of different frequencies travel at slightly different speeds when they enter a medium like glass or water. This is a violation of Big Rule 1 for waves! However, light waves are an exception to this rule. *dispersion= variation in wave speed for different frequencies; changes the index of refraction *blue light refracts more than red light in a prism *when white light passes through a prism, it gets split into colors of the rainbow due to dispersion, (this is a special case of refraction). *actual rainbows that you see outside are created by refraction by water droplets (geometrical optics)

Hund's Rule:

when you fill a subshell w more than 1 orbital (x, y, z), you first fill each orbital w a single e- and w the same spin. The reason for Hund's rule is that electron-electron repulsions in doubly occupied orbitals makes them higher in energy than singly occupied orbitals (electronic structure)

Electrostatic induction:

where a charged object, for example +Q, induces the atoms which make up an insulator to become polarized. That is, their electrons will feel a tug toward +Q, causing the atoms to develop a partial negative charge (towards Q+), and a partial positive charge (away from +Q). *induction does not involve any type of conduction *the classical example of electrostatic induction is picking up pieces of paper using a comb which was rubbed against fur (Electrostatics)

Which ion is more stable? A)Fe²⁺ B)Fe³⁺

you are comparing [Ar]3d⁶ vs [Ar]3d⁵. Fe³⁺ is more stable bc it has a half filled d subshell (electronic structure)

When you add increasing amounts of solute, what happens to the bp?

bp is a colligative property. When you add more solute, BP ELEVATION occurs. Solute molecules are attached to solvent molecules and act as "anchors." As a result, more energy is required for a liquid to enter the gas phase, thus bp elevates. BP elevation, ΔT = k i m *ΔT gives you the change in boiling temp, k is the solvents bp depression constant, i is the solutes van't hoff factor, m is the molality of the solution **wants to stay a liquid (gas phase)

Troughs:

dips/low-points of a wave. The distance between one trough to the next gives you the wavelength. (periodic motion)

Define dispersion. How does the index of refraction depend on the frequency of light?

dispersion is the separation of individual colors (frequencies) of a beam of light due to the small dependence of refractive index on frequency. Higher frequencies have higher indices of refraction

Since charge in motion constitutes a current, we can say that magnetic fields are produced by __________.

electric currents (Magnetism)

Define electric potential and voltage. In what units are they measured?

electric potential: electric potential energy per charge, measured in volts, where 1V=1 J/C voltage: the change in electric potential energy

Electromagnetic waves:

electromagnetic waves are the oscillations which produce electromagnetic radiation. Includes radio, microwave, IR, visible, UV, x-rays, gamma rays. Electromagnetic radiation consists of electric and magnetic fields which oscillate in phase w each other and are mutually perpendicular to each other and to the propagation direction. For this reason, electromagnetic waves are transverse waves. The direction the wave's electric field oscillates is called the direction of polarization of the wave. (geometrical optics)

In electrochemical cells:

electrons always flow from the anode to the cathode *Mnemonic= electrons flow from A to C (electrochemistry)

Avogadro's Law:

equal volumes of two gases will also contain equal number of moles of each gas, given ideal conditions (ideal gas at STP) PV=nRT R is constant, and at STP, pressure and temperature are also constant V/n = RT/P, if you plug in STP values, you'll end up with V/n=22.4L/mol (gas phase)

For a particular rope, its found that the second-harmonic frequency is 8Hz. What's the fifth-harmonic frequency?

f=(n)(fundamental frequency) → fundamental frequency=f/n → fundamental frequency=8/2 → 4Hz is the fundamental frequency So, f=(n)(fundamental frequency) → f= (5)(4) → 20Hz is the fifth-harmonic frequency (periodic motion)

A piano tuner strikes a tuning fork at the same time he strikes a piano key w a note of similar pitch. If he hears 3 beats per second, and the tuning fork produces a standard 440 Hz tone, then what must be the frequency produced by the struck piano string?

fbeat= |f1 - f2| 3= |f1 - 440| → f1= 3+440 → f1= 443 Hz OR 3= |440 - f2| → f2= 440-3 → f2= 437 Hz Answer: 437Hz or 443Hz (sound)

A sprinter runs 300m north, then 400m east, which takes 100 seconds. What was his average speed? What was the magnitude of his average velocity?

first, he is running 300m north and 400m east. Draw this out. This will give you a right triangle. So, a^2+b^2=c^2 → 3^2 + 4^2 = c^2 → 25 = c^2 → c=5, or c=500. This is the displacement. (note, we simplified this by removing the zeros, then adding them back at the end). *average speed = 700m/100s → 7m/s *average velocity = 500m/100s → 5m/s (translational motion)

As a high speed chase begins, a police car travels at a speed of 40m/s directly toward the suspect's getaway car, which is traveling at a speed of 70m/s, trying to outrun the pursuing police. The frequency that the suspect hears will be what percentage of the frequency of the police car's siren? Speed of sound= 340 m/s

fobserver = fsourcel (vsound - vobserver)/(vsound - vsource) → fobserver=fsource(340-70)/(340-40) → fobserver=fsource (270/300) → (90%)fsource (sound)

What is the relationship between the cross-sectional area of a flow tube and the flow speed?

for incompressible fluids, f1=f2, or A₁v₁=A₂v₂. Thus, A and v are inversely proportional

State the three properties of electromagnetic radiation

frequency, wavelength, and energy

Define fundamental frequency. How do higher harmonic frequencies depend on the fundamental?

f₁=lowest wave frequency of traveling waves that will produce a standing wave; fn=(n)(f₁)

Give a formula for calculating g

g=GM/r²

Rank in order of wavelength, from shortest to longest, the regions of the EM spectrum

gamma rays < X-rays < UV < visible light < IR < microwave < radio waves

In which phase do molecules have the most energy?

gas phase

At a given temp, which gas molecules travel faster: those w small molecular weights or large ones?

gases w smaller molecular weights travel faster

Radiolabeled vitamin B₁₂ containing radioactive cobalt-58 is administered to diagnose a defect in a pt's vitamin-B₁₂ absorption. If ⁵⁸Co has a half-life of 72 days, approximately what percentage of the radioisotope will still remain in the pt a year later? A) 3% B) 5% C) 8% D) 10%

half life=72 days 365 days in one year ~5 half life to 6 half life 1 half life, 100%→50% 2 half life, 50%→25% 3 half life, 25%→12.5% 4 half life, 12.5%→6% 5 half life, 6%→3% Answer= A, 3% remains

Reduced non-metal anion:

halogens tend to gain a single electron, either forming a diatomic molecule or becoming a reduced non-metal anion (the periodic table; electronic structure)

Define ideal fluid flow

ideal fluid flow occurs when the fluid is incompressible, has no viscosity, is laminar, and has a steady flow rate

Impulse:

impulse is equal to the force multiplied by the time during which it acts. It is expressed as: J=FΔt, with units of Nᐧs -impulse can additionally be expressed as, J=Δp *impulse is equal to the change in momentum *if you apply force to an object for some duration of time, the object will gain some momentum (it will begin to move) -impulse is a vector, it has direction. Can be a positive or negative value -this is why baseball players are taught that after you hit the ball, swing through with your bat. A force exerted for a longer time interval on the ball will result in a greater impulse (the ball will go farther) -a box sitting on the floor. If you apply a huge force to this box for a long time interval (huge impulse!), you will push it across the floor. -a box sitting on the floor. If you apply a small force to this box for .005 seconds, a very tiny time interval, (tiny/little impulse), the box will most likely not move. (Equilibrium)

Mechanical energy in an electric field:

in the absence of non-conservative forces (no friction, no drag, etc), mechanical energy is conserved. That is, KE + PE=constant, so Δ(KE+PE)= 0. This gives us: ΔKE = -ΔPE So, ΔKE and ΔPE always have opposite signs (Electrostatics)

Efficiency involving simple machines:

in the real world, the actual mechanical advantage of a machine is less than its mechanical advantage in the ideal world. The efficiency of any machine measures the degree to which friction and other factors reduce the actual work output of the machine from its theoretical maximum. This can be calculated by using the ratio of the useful energy output vs the supplied energy input, given by: Efficiency (%) = Woutput/Einput (energy of point object systems)

Vasoconstriction:

increase BP (circulatory system)

If a projectile's launch angle is θ₀, what are the components of its initial velocity?

initial horizontal speed: vinitialx=v₀cosθ initial vertical speed: vinitialy=v₀sinθ

What happens at the molecular level when a substance changes phase?

intermolecular forces are formed or broken

During an isometric biceps curl, when the elbow is at about 90 degrees, does the biceps or the dumbell that is held in the hand exert a greater magnitude of torque on the forearm? Which exerts the greater magnitude of force?

isometric = relating to or denoting muscular action in which tension is developed without contraction of the muscle. The muscle is tense but not moving, in static equilibrium. So, static equilibrium means the CCW torque = CW torque Since force is directed at a 90 degree angle, 𝛕=rF, and rFbicep=rFdumbell *dumbbell has a larger radius, so the dumbbell must exert a smaller force. *the bicep has a smaller radius, so the bicep must exert a larger force. (Equilibrium)

What happens to spacing between successively higher energy levels in an atom as you move farther from the nucleus?

it decreases

Standing sound waves in pipes:

just as we can have standing waves on a rope caused by the interference of two oppositely directed transverse waves w equal amplitudes, standing waves in a pipe can be caused by the interference of two oppositely directed LONGITUDINAL waves of equal amplitude. pipes are often classified as either: 1)open pipes (open on each end) 2)closed pipes (closed on one end) (sound)

Magnetic fields and magnetic forces:

magnetic fields, B, are created by moving electric charge. In other words, magnetic fields are produced by electric currents. *a magnetic field can only exert a force on a charge that is moving through the field. A magnetic field will exert no force on a charge that's at rest. The magnitude of the magnetic force is given by: F = |q| vBsinθ, where F is the force of the magnetic field on a moving charge, q is a charge moving through the magnetic field, v is the velocity of the charge moving through the magnetic field, B is the magnetic field strength, and θ is the angle between v and B. *B has units of tesla, T. Newton per amp-meter. *force is always perpendicular to both the magnetic field, B, and to the velocity, v, of the particle. Think of things in the x, y, and z plane. *magnetic field, B, and velocity, v, do not have to be perpendicular. They can be in any direction *if a charged particle's velocity, v, is parallel to the magnetic field lines, B, then you get sin(0)= 0 or sin(180)=0, resulting in the force of the magnetic field being equal to zero. So, a charge can be moving through a magnetic field and yet feel no force if its direction of motion is parallel to the magnetic field lines. *if a charged particle's velocity, v, is perpendicular to the magnetic field lines, B, then the object is undergoing uniform circular motion *sometimes sinθ is omitted from the equation if it is assumed that v and B are 90° relative to each other; sin(90)=1, so the equation becomes F= |q| vB. (note: when v and B are 90 degrees to each other, the particle is undergoing uniform circular motion!) *the direction of the force depends on whether the charge q that moves through the field is positive or negative. Use the right hand rule to find the direction of force (Magnetism)

Ionic bonds occur between:

metal + nonmetal *big diff in electronegativities, for ex, HCl

Covalent bonds occur between:

nonmetal + nonmetal, OR, nonmetal + transition metal *little/small diff in electronegativities, for ex, MnO4

What property is used to measure the amount of a given gas in a mixture of gases?

partial pressure

Suspension:

particles are >500nm. Things are mixed as a particle level and will not stay mixed. Will eventually settle at the top or the bottom. For ex, chocolate milk or ketchup. Before using, you should shake the bottle bc particles dissolve at the bottom. *way to remember: any Sauces are Suspensions (sauces like ketchup, A1, you need to shake)

What letter stands for the principal quantum number? What is the range of possible values for this number?

principal quantum number, n n=1 to n=∞

Pulley systems:

pulleys reduce the force you need to lift an object. The catch is that it increases the required pulling distance. The distance of pulling increases by the same factor that the effort decreases. SIMPLE PULLEYS: 1) when there is no moving pulleys, you must pull w a force equal to the weight of the box. With every 1m you pull, the box goes up 1m 2) when there is one moving pulley, the force needed to pull is halved bc strings on both sides of the pulley contribute equally. If the box is 100N, you supply 50N (which is transmitted to the right-hand rope) while the left-hand rope contributes the other 50N. Bc effort here is halved, the distance required to pull the box is doubled. 3) When there are two moving pulleys, when you pull on one rope it gets transmitted to a system where 4 ropes pull on the load. Thus, you can pull the 100N box w only 25N. However, for every 4m you pull, the box only goes up 1m (Force)

Effusion:

random molecular motion, causing a substance to escape a container through a very small opening *remember: effusion = exit = immigration (gas phase)

Aufbau principle:

shells/subshells of lower energy gets filled first. For ex, 1s fills first, then 2s, then 2p... etc. (electronic structure)

Homogeneous mixture:

solution where components do mix. Three types of homogeneous mixtures: suspension, colloid, solution

Heterogeneous mixture:

solution where components do not mix. For ex, water and oil. Do not mix together.

Define sound intensity. How is sound level calculated from sound intensity?

sound intensity, I=power/SAsphere sound level, in dB, β=10log(I/I₀)

Turpentine has a specific gravity of 0.9. What is the density of this liquid?

specific gravity = 𝝆/𝝆water → .9=𝝆//1000kg/m^3 → 𝝆=900 (fluids)

Define standing wave, node, antinode, harmonic frequency, and harmonic wavelength

standing wave= superposition of two oppositely-directed traveling waves that results in a single, non traveling wave node=point of zero displacement antinode=point of maximum displacement harmonic frequency= common frequency of traveling waves that will produce a standing wave harmonic wavelength= common wavelength of traveling waves that will produce a standing wave

Torricelli's result:

statement that the speed, v, of a liquid flowing under the force of gravity out of an opening in a tank is given by: Vefflux = √2gD, where D is the distance from the surface of the liquid down to the hole *hydrodynamics (fluids)

Hooke's Law (elasticity of solids):

states that stress and strain are proportional (fluids)

Dalton's Law:

states that the total pressure of a mixture of gases is equal to the sum of their partial pressures. Expressed by: Ptotal=Pa + Pb + Pc + .... -so, if we know the partial pressures we can determine the total pressure. -and, if we know the total pressure, we can figure out the individual partial pressures by using the mole fraction. *the partial pressure of a gas is equal to its mole fraction times the total pressure, Pa = (Xa)(Ptotal) *Dalton's Law relates partial pressures to mole fraction (gas phase)

Define streamline, laminar flow, and turbulent flow

streamline=a line in a flow tube which is everywhere parallel to the direction of fluid flow at a particular instant laminar flow=smooth, well-behaved flow, where the flow velocity at any point remains constant turbulent flow= chaotic flow in which streamlines cross and do not follow the contours of the flow pipe

Define stress and strain. In what units are they measured? What is the relationship between these quantities?

stress=force/area *tensile or compressive stress= force perpendicular/A *shear stress= force parallel/A stress has units of N/m² strain=∆L/L strain has no units stress α strain

Surface tension:

surface tension gives the surface of a liquid the ability to support things very light. For ex, insects can walk on water due to surface tension. Surface tension is due to the attraction between the molecules of the solvent (fluids)

State the directions of tangential, centripetal, and angular acceleration

tangential= tangent to circle centripetal or radial=towards center of circle angular=directed out of circle

Condensation point:

temp (at a given pressure) that a gas begins to condense into a liquid *condensation point, bp, and vaporization point are the same

Boiling point:

temp (at a given pressure) that a liquid begins to turn into a gas *bp, condensation point, and vaporization point are the same

Melting point:

temp (at a given pressure) that a solid begins to melt into a liquid *mp and fp are the same

Freezing point:

temp (at a given pressure) that liquids begin to freeze into a solid *fp and mp are the same

What quantity is specified by the average kinetic energy of the molecules of a substance?

temperature

What two things does vapor pressure depend on?

temperature and IMF's

Calorie:

the amount of heat required to raise the temp of 1g of water by 1℃. *converting from calories to jewels, 1cal = 4.2J *note: the term "Calorie, C" in our diets/eating behavior is actually a kilocalorie (10³cal), and should be written w a capital C.

Properties of boiling point:

the bp is the temperature in which the vapor pressure of a liquid becomes equal to atmospheric pressure -bp, condensation point, vaporization point are all the same thing -The bp occurs when Pvap = Patm 2 main properties: 1)external P is directly proportional to bp, Patm∝bp *so, when you increase the Patm, the bp also increases. Ex, when you go to the top of Mt. Everest, the Patm decreases compared to sea level. Therefore at the top of Mt. Everest, the bp is lower bc the Patm is lower. Easier for Pvap=Patm, so lower bp. **why people who climb Mt. Everest can get dehydrated easily. They are more easily evaporating water, so more water is lost. Can lead to dehydration 2)intermolecular forces are directly proportional to bp, IMF∝bp SUMMARY: bp∝IMF∝Patm -if intermolecular forces are small, the liquid has a high vapor pressure *little heat energy will have to be added to separate the molecules, so the bp will be low -if there are strong intermolecular forces, the molecules will be strongly attracted to each other. Few molecules will enter the gas phase, and the vapor pressure will be low. *more heat energy will be required to separate the molecules, so the bp will be higher (gas phase)

Center of mass:

the center of mass in a cartesian coordinate is the point obtained by doing a weighted average for all the positions by their respective masses. It is given by: xcm= (m₁)(x₁) + (m₂)(x₂) + .. // m₁+m₂ + .. -the same equation holds true for the y direction -the center of mass of the earth and a chicken in space is going to be almost at the center of the earth, bc the chicken is tiny, and its coordinate is weighed so -the center of mass between two chickens in space is going to be right in the middle of the two chickens, bc their positions are weighed equally -the center of mass for a sphere is at the center of the sphere -the center of mass of a donut is at the center of the donut (the hole) (Force)

Describe the Doppler effect

the change in observed frequency of an acoustic (or EM) wave caused by relative motion between source and detector

What do the constants a and b account for in the van der Waal's equation for real gases?

the constant a accounts for the intermolecular forces between gas molecules and b accounts for the molecular volume of the gas particles

Potential difference:

the difference between two potentials. Expressed as: Δɸ= ɸfinal - ɸinitial *potential difference is used in scenarios such as the difference in potential between the two plates of a capacitor, or the positive and negative terminals of a battery (Electrostatics)

Alternating current (AC):

the direction of current in a circuit changes; electrons first flow one way, then the opposite way, then back again. The electric current that we use in our homes and offices everyday is AC current. *producing an alternating voltage (and thus an alternating current) supplies electricity to entire cities and is easier than producing a steady, direct voltage. (Circuit Elements)

Define the direction of polarization of an electromagnetic wave

the direction of polarization if the direction of oscillation of electric field

Potential energy:

the energy an object has by virtue of its position. Remember, units of any energy is always in J -there are diff kinds of PE bc there are diff kinds of forces. *Three types of PE, they are: gravitational, electrical, and elastic potential energy 1) PE=mgh, (gravitational, local) *local bc it only works on the surface of the earth *on earth, g is 10Nkg. The value of g is larger for planets w a higher mass to radius ratio. PE= GmM/r² (gravitational, general) *this is the general formula for gravitational PE; allows you to calculate g. *here, G is the universal gravitation constant. Will be given on test 2) PE=1/2kx², (elastic, spring) *x is the distance of the end of the spring from its equil position *k is the spring constant *stiff springs have a larger k bc they are harder to stretch (it takes more energy to stretch them) (energy of point object systems)

Dynamics:

the explanation of motion in terms of forces that act on an object. *remember, kinematics was just the description of motion in terms of an object's position, velocity, and acceleration. It did not take forces into account. (Force)

Young's modulus:

the ratio of stress/strain. This ratio is constant until you reach the elastic limit, where things get permanently deformed (fluids)

Angular momentum:

the rotational equivalent of linear momentum. -we know that linear momentum is defined as p=mv -the rotational version of mass is the moment of inertia, I -the rotational version of velocity is the angular velocity, ω -therefore, the angular momentum, L is defined as: L=rmv=lω, where r is the radius, m is mass, v is velocity (Equilibrium)

Calorimetry:

the science of measuring changes to determine heat transfer. Matter can absorb or release energy w/out undergoing a transition. We observe this as an increase/decrease in the temp of a substance. Calorimetry is performed w a calorimeter, which must be very insulated. A "constant pressure calorimeter" is used for many reaction. There is also a "bomb calorimeter" which allows for pressure changes

Nucleons:

the smallest unit of any element is the atom. All atoms have a central nucleus, which contains protons and neutrons. p+ and n together are collectively called nucleons (atomic nucleus)

Diffraction:

the spreading (diffusion) of waves around edges of apertures and obstacles *the redistribution of a wave's intensity is known as diffraction *you can hear sounds from the other side of a building bc sound spreads *shining light through a hole will not produce a dot of light, instead, it is a diffuse circle *diffraction is the basis for the single and double slit interference experiments w light (geometrical optics)

Electrochemistry:

the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction ("redox") reaction. (electrochemistry)

Superposition of electric fields involving like charges:

the superposition of electric fields occurs when two or more source charges are present, whose electric fields overlap. Can be two positive source charges or two negative source charges. (Electrostatics)

Terminal potential of a battery:

the voltage across the terminals of a battery *if the battery has no internal resistance, then terminal potential of the battery = emf *internal resistance of a battery is like a resistor right next to the battery connected in a series. Terminal potential of the battery= emf - internal resistance (Circuit Elements)

In a ¹H NMR spectrum, a signal integrates for 3H and is split into a triplet. What does this indicate about the structure of the molecule?

there is a methyl group adjacent to a -CH₂- group

Which of the following is the largest? A)Cl- B)Ar C)K+

these are all isoelectric to each other! Therefore, the one with the most negative charge has the largest ionic radius. Here, that is Cl- (periodic table; group and row)

Water phase diagram:

this phase diagram follows the same general trends as other phase diagrams, except the solid-liquid boundary line is slanted to the left. Has a slight negative slope. This is bc water is more dense in the liquid phase compared to the solid phase. -for water, an increase in pressure at constant temp favors the liquid phase, not the solid phase (as is the case for most other substances). -this is why we can ice skate. As the blade of the skate contacts the ice, the pressure increases, melting the ice under the blade and allowing the skate to glide over the liquid water. As the skater moves across the ice, each blade continually generates a thin layer layer of liquid water that refreezes as the blade passes. *note: the properties of CO2 would never allow for skating bc CO2 will never turn to a liquid when the pressure is increased (why its called dry ice!)

Nickel-Cadmium batteries:

type of rechargeable battery; this is the normal rechargeable batteries you buy at the store. NiCad batteries are a type of galvanic cell that uses a metallic Cd anode and a nickel oxide hydroxide (NiO(OH)) cathode. To facilitate these reaction, NiCd cells contain an alkaline KOH electrolyte *recharging the battery involves applying a voltage to reverse the electron flow (electrochemistry)

Hooke's Law (oscillations):

used when looking at simple harmonic motion of a spring. The force exerted by the spring, the restoring force, is given by Hooke's Law: F=-kx, where F is the restoring force, k is the spring constant (stiffer springs have a higher k value), and x is the displacement (the amplitude, A, is the maximum x value) (periodic motion)

What is the relationship between wave speed, wavelength, and frequency?

v=fλ

The speed of a transverse wave on a rope is given by:

v=√tension//linear density, where tension is how tight the rope is and linear density is how dense the rope is (is the rope not dense (like tooth floss), or dense (like the ropes that hold cruise ships ashore). *tense, light strings produce faster transverse waves *loose, heavy strings produce slower transverse waves (periodic motion)

Which electrons do transition metal atoms lose first when ionized?

valence s electrons

Ultrasound:

vibrations whose frequency is too high to hear (sound)

If an object were thrown straight upwards w an initial speed of 8m/s and it took 3sec for the object to strike the ground, from approximately what height was the object thrown?

v₀= 8m/s vf=? a=10 (the object's initial displacement is up, so used -gravity value) d=? t=3 sec d=v₀t + ½ at² → d= -21 m or just 21m (translational motion)

Argon, at a pressure of 2atm, fills a 100mL vial at a temp of 0C. What would the pressure of the argon be if we increased the volume to 500mL, and the temp is 100C?

we are not told the number of moles, but it does not matter since moles are staying the same! So, nR is constant, and we have: P1V1/T1 = P2V2/T2 → P2 = (2atm)(.1L)(373K) // (.5L)(273K) → P2 = .55atm (gas phase)

Standing sound waves in an open pipe:

when a pipe is open on both ends: -there is antinodes at both ends (antinodes are also called pressure nodes; areas of constant pressure) -the distance between antinodes is equal to a whole number of half wavelengths. The formula for wavelength and frequency are the same as for the string attached at each end: 𝝺= 2L/n, and 𝝺=𝝺fundamental/n f= nv/2L, f=(n)(ffundamental) *where the harmonic number, n, can be an odd or even number, and v refers to the speed of sound in air Remember: -node=point where there's no oscillation -antinode= point where there's maximum oscillation -the distance between any two consecutive nodes is always ½ the wavelength (sound)

Equilibrium:

when something is in equil, the vector sum of all forces acting on it = 0. When something is in equil, it is either at rest or moving at constant velocity. When something is in equil, there is no acceleration. There are two kinds of equil: -translational equil= the net forces acting on an object = zero. This means the translational acceleration, a, is zero. -rotational equil= the net torques acting on an object = zero. This means the rotational acceleration, ⍺, is zero. (Equilibrium)

Interference of waves:

when waves superimpose on eachother, they interfere. The amplitude of the resultant wave will depend on the amplitude of the combining waves and on how these waves travel relative to each other. -when in phase, waves add; (crest meets crest), the resulting wave has a greater amplitude. This is constructive interference. In phase waves are at 0°, 360°, or 2𝜋 radians to each other. -when out of phase, waves subtract; (trough meets crest), the resulting wave has a smaller amplitude. This is destructive interference. Out of phase waves are at 180° or 𝜋 radians to each other. -if two waves, (wave 1 and wave 2) are starting from some point, and each is traveling a different distance, d, to reach an object, (for ex, like a cork floating in water), how can you determine if the two waves will be in phase or out of phase once they reach the cork? Look at the path distance between the two, d₂-d₁. If the path distance is a whole number, the waves will be in phase and will experience constructive interference once they reach the cork. If the path distance is not a whole number, the waves will be out of phase and will experience deconstructive interference once they reach the cork. *for ex, if wave 2 travels an integer number farther than wave 1, the crests will arrive at the same time. If wave 2 travels ƛ/2, 3ƛ/2, 5ƛ/2, etc, farther than wave 1, the crests from one wave will arrive simultaneously w a trough from the other wave (periodic motion)

If a rope of length 6m supports a standing wave w exactly four nodes (which includes the ends of the rope), what is the wavelength of the standing wave?

ƛ=2L/n → ƛ=2(6m)/3 → ƛ=4m (periodic motion)

Define angle of incidence, angle of reflection, angle of refraction, and index of refraction

θincidence= angle that the incident beam makes with the normal θreflection=angle the reflected beam makes with the normal θrefraction= angle the transmitted beam makes with the normal index of refraction: n=c/v, where c is speed of light through a vacuum (3x10⁸m/s) and v is speed of light through medium under study

An object of mass 10kg moves w a velocity of 4m/s to the north. What is its KE? What would happen to the KE is the speed of the object doubled?

*KE is scalar, so we only care about the speed of the object. The direction is irrelevant. So, KE=1/2mv² → KE=½(10kg)(4m/s)² → 80J *bc KE is proportional to v², if the velocity increased by a factor of 2 then KE would increase by a factor of 2²= 4 (energy of point object systems)

A temperature of 273C is equivalent to: A)-100K B)0K C)100K D)546K

*first, eliminate choice A, bc K can never be negative! K= C + 273 → K= 273 + 273 → 546K (gas phase)

An electric field pushes a proton from one position to another such that the change in potential is -500V. By how much does the KE of the proton increase, in electron volts?

*the change in PE is: ΔPE= qΔɸ → (e)(-500V) → -500eV *the change in KE is: +500eV (Electrostatics)

Define transverse wave and wavelength. Define longitudinal wave, compression, and rarefaction

*transverse wave: oscillation of medium perpendicular to propagation of wave *wavelength, λ: length of one cycle of wave (from crest to crest) *longitudinal wave: motion of medium ‖ propagation of wave *compression: region of maximum pressure *rarefaction: region of minimum pressure

What is the electric potential at a distance of r= 30cm from a source charge Q= -20nC?

*using the electric potential formula, ɸ=k Q/r, (9x10⁹ Nᐧm²/C²)(-2x10^-8 C) / (30x10^-2 m) → -600V (Electrostatics)

In this redox reaction, what has been oxidized vs reduced? What is the oxidizing agent vs the reducing agent? Also, what is the ion-electron half-reactions? Fe + 2HCl → FeCl₂ + H₂

-Fe is oxidized, and is thus the reducing agent -H is reduced, and is thus the oxidizing agent -half-reactions show the oxidation and reduction separately; ion-electron equations show only the oxidized and reduced species and the e- involved *oxidation= Fe → Fe²⁺ + 2e- *reduction= 2H+ + 2e- → H₂ (electrochemistry)

Mass spec is useful for:

-Measuring the molecular weight of a molecule -Identify the molecule by fragmentation patterns -Identity heteroatoms by their characteristic isotope ratios (for ex, Br is present in two major isotopes, so if a molecule contains Br you will have two tall peaks. Cl also is present in two major isotopes) note: heteroatom is any atom that is not C or H (molecular structure and absorption spectra)

Gas:

-atoms/molecules fly apart from one another and do not experience intermolecular forces -density is not constant -high kinetic energy -high entropy -easy to compress -flows to fill a container

Concave mirror ray diagram:

-center of curvature, C or R or r= the center of the sphere or circle; the radius -focal point or focal length, f= the distance from the mirror to the focal point. The focal length is half the radius of curvature, f=1/2r *converging systems always have a +f Tend: real/inverted and small, and getting bigger along the way until it becomes virtual/upright. If object is behind the focal point (father from mirror): o>R you will see a real, inverted, smaller image o=R you will see a real, inverted, same-size image R>o>f you will see a real, inverted, larger image If object is inside the focal point (closer to mirror): o=f you will see nothing. An image is not formed o<f you will see a virtual, upright, larger image (geometrical optics)

Ball 1 and ball 2 are rolling toward eachother at the same speed, 5m/s. Ball 1 has a mass of m₁=8kg, and ball 2 has a mass of m₂=2kg. After the collision, ball 1 and ball 2 stick together and slide frictionlessly across the table. What's their common velocity after the collision?

-choosing right as the + direction, we have v₁=5m/s and v₂=-5m/s -using the conservation of momentum, we know ptotalbefore = ptotalafter m₁v₁ + m₂v₂ = (m₁ + m₂)v' → (8kg)(5m/s) + (2kg)(-5m/s) = (8kg+2kg)v' → v' = 3m/s (Equilibrium)

Valence electrons:

-e- in the outer shell; the sum total of all the electrons in the highest energy level. -ranges from 1 to 8 from left to right of the representative elements -the valence electron rule does not apply to transition metals (the periodic table; electronic structure)

Noble gases:

-group 8, p-block -full valence shell of 8, high ionization energy, low e- affinity -do not react, INERT -found in the oxidation state of 0 (the periodic table; electronic structure)

Going from a solid → liquid → gas:

-heat must be absorbed, +ΔH, this is an endothermic process, energy is absorbed -can occur by increasing the temp -internal KE increases -entropy increases, +ΔS, more disorder -solid → liquid = fusion/melting *the amount of heat needed to do this= heat of fusion, ΔHfus -liquid → gas = vaporization/boiling *the amount of heat needed to do this= heat of vaporization, ΔHvap -sublimation= going straight from solid → gas

When will objects float vs sink?

-if Pbottom > Ptop, then object will feel a net force upwards in y direction until Pbottom = Ptop and Fnety=0. Object will float in static equilibrium. -if Pbottom < Ptop, then object will feel a new force downward in y direction. Object will sink. *if 𝝆object < 𝝆fluid, then the object will float. The Fweight is less than Fbuoyant *if 𝝆object > 𝝆fluid, then the object will sink. The Fweight is greater than Fbuoyant *if 𝝆object = 𝝆fluid, then the object will hover in static equilibrium underneath the fluid (fluids)

What are the two Big Rules for all waves?

-rule 1= the speed of a wave is determined by the type of wave and the characteristics of the medium, not by the frequency. A wave traveling through a medium has a constant velocity. If frequency increases, wavelength decreases. If frequency decreases, wavelength increases. Either way, the velocity is constant. -rule 2= when a wave passes into another medium, its speed changes, but its frequency does not. In other words, frequency is constant between media. If a wave is traveling from air into water, (a more dense medium), once the wave hits the water it will develop a larger wavelength and thus a larger velocity. The frequency, however, is the same. The rate in = rate out. *remember, sound waves have a wavelength, a speed, a frequency, a period, and an amplitude. The equation v= 𝝺f holds, as do the two Big Rules for waves (sound)

Redox titration graph:

-the titration curve is plotted in terms of: cell potential (measured in Volts), on y axis. Vs the volume of titrant added, on x-axis. *important places on the graph: -equivalence point= when solution changes color (once endpoint is reached) -half-equivalence point= the ratio of oxidized and non-oxidized reactants are present at equal concentrations (Q=1). The value of E (measured against whichever reference electrode one chooses) is equal to the value of E° for your redox couple being titrated. We see this w the Nernst equation: E = E° - (RT/nF)lnQ *since ln(1)=0, E = E°

Electrolytic Cells:

-unlike a galvanic cell, an electrolytic cell uses an external voltage source (such as a battery) to create an electric current that forces a NONSPONTANEOUS redox rxn to occur. This is known as electrolysis. -nonspontaneous rxn, requires an external electric power source -total E of reaction is negative -anode is positive (wants e-, but is instead getting rid of e-) -cathode is negative (wants to get rid of e-, but is instead getting e-) EXAMPLE: -a electrolytic cell, the anode is made of chloride ions (Cl-). The cathode is made of sodium ions (Na+). -an external battery is used. It forces electrons to be removed from chloride ions. It then forces sodium ions to accept these electrons. -the chloride ions are oxidized to produce chlorine gas (2Cl- → Cl₂(g) + 2e-). The sodium ions get reduced to sodium metal (Na+ + e- → Na(l)) (electrochemistry)

Explain weight in terms of the normal force (horizontal surface vs incline plane):

-when something is laying still on a horizontal surface, the normal force is equal and opposite to the weight (usually, unless you are applying an additional force! like pushing on a book that is laying on the floor) -when something is laying still on an inclined plane, the normal force and friction force adds up in a vector fashion to equal the weight (Force)

Reducing agents:

-will reduce something else, and in turn become oxidized (gives e-, an e- donor) -an atom that is oxidized in a reaction loses e- to another atom. We call the oxidized atom a reducing agent/reductant, bc by giving up e-, it reduces another atom which gains the e-. -common reducing agents = STUFF W A LOT OF HYDROGENS; elements with low electronegativities and ionization energies (like Na, Mg, Al, Zn); metal hydrides, like LiAlH4, NaBH4, NaH, and CaH2 (bc they contain the H- ion) *most common reducing agents: -hydrogen, H₂ -metals, such as K, Na, Mg, Al, Zn → low EN and low IE -zinc with hydrochloric acid, Zn/HCl → metal hydride -tin with hydrochloric acid, Sn/HCl → metal hydride -lithium aluminum hydride, LiAlH₄ (commonly abbreviated LAH) → metal hydride -sodium borohydride, NaBH₄ → metal hydride -lewis bases/nucleophiles (donates an e- pair) (electrochemistry)

Kirchhoff's Rules:

1) the sum of the voltage-drops across the resistors in any complete path is equal to the voltage of the battery 2) the amount of current entering a parallel combination of resistors is equal to the sum of the currents that pass through the individual resistors (Circuit Elements)

Examples of objects which undergo simple harmonic motion:

1)object undergoing UCM (going around a circle at a constant speed 2)mass oscillating on a spring 3)pendulum oscillating back and forth *graph of sin when you plot the x axis position against time (periodic motion)

Write 0.0055 in scientific notation Write 700 in scientific notation

5.5 × 10⁻³ 7x10²

Which has the highest vapor pressure A)CH₄ B)H₂O C)CH₃OH D)(CH₃)₂O

A molecule w the highest Pvap must have the lowest IMF's. More IMF's=lower Pvap CH₄ only has LDF H₂O has H-bonding CH₃OH has H-bonding (CH₃)₂O has dipole-dipole So, H-bond > dipole-dipole > LDF **CH₄ has the highest Pvap, lowest IMF's (gas phase)

Whenever you see a unit squared or cubed what does that mean?

A unit squared or cubed means you are looking at something in two or three dimensions. unit = one dimension unit² = two dimensions (on a 2D plane, xy coordinates) unit³ = three dimensions (on a 3D plane, xyz coordinates)

The mass of a crate, m, is 20kg and the coefficient of kinetic friction between the crate and the floor is 0.4. You apply a force of 100N parallel to the crate, moving the crate a displacement of 6m. A)how much work is done by F? B)how much work is done by the normal force? C)how much work is done by gravity? D)how much work is done by the force of friction? E)what is the total work done on the crate

A) bc F is parallel to d, the work done by F is simply W=Fd → W=(100N)(6m) → 600 J B) the Fn is perpendicular to the floor and to d. This is a 90 degree angle, cos(90)=0. So, the work done by Fn is zero *there is no displacement in the y direction, all forces cancel C )the Fg is also perpendicular to the floor and to d. This is a 90 degree angle. So, the work done by Fg is zero *there is no displacement in the y direction, all forces cancel D)First, Ff=μFn So, Fn=mg → Fn=(20kg)(10N/kg) → 200N = Fn Thus, Ff=μFn → (.4)(200N) → 80N = Ff Finally, W=Fdcosθ → W=(80N)(6m)cos(180) → -480 J *work is a negative value bc Ff acts opposite the direction of displacement E)to find the total work, add up the work done by each of the forces which act on the crate. So, W total= W force + W friction → W total=600J + (-480J) → 120 J *note, we omitted the work done by Fn and Fg bc they were both zero (Work)

A) How much work is required to stop a 1000kg car moving at 20m/s? B) if the breaking force is 20,000N, how far will the car travel before stopping?

A) first, we know that W=Fdcosθ. And W=ΔKE=1/2mv². Here, we have mass and velocity. So use W=ΔKE equation. W=KEf-KEi → W=0-1/2mv² → W= -½ (1000kg)(20m/s)² → W=-2x10⁵ J B) Now, using W=Fdcosθ, and force is parallel to displacement, cos(0)=1, we get W=Fd. So, 2x10⁵J = Fbrakes(d) → 2x10⁵/20,000 → d= 10m (Work)

Define electrolyte

An electrolyte is a solute that dissociates into charged particles in solution (has an i value greater than 1)

What is a compression wave?

Another word for a sounds wave! Sound waves are also called compression waves bc they have compressions (areas of high pressure) and rarefactions (areas of low pressure) (sound)

A car is going around a circular turn of radius 12m. The coefficient of friction between the car's wheels and the ground is 0.3. What is the maximum speed at which the car can take the turn?

Answer: v=6 We know that Fc=mv²/r. We know that Ffs=𝞵Fn. So, Fc = Ffs. *see pic (Force)

The photon model of light is necessary to explain each of the following experimentally observed effects except: A) the ejection of electrons from a metal surface w light shining upon it B) the stopping voltage as a function of light frequency C) the instantaneous detection of a current following the application of light to the metal surface D) the fact that an intense infrared light may result in no measured current where a dim UV light results in measured current

Answer=A. This was predictable by the wave theory of light. (electronic structure)

Kinematics:

Description of motion in terms of an object's position, velocity, and acceleration (translational motion)

Converting from C to F:

F = (C)(1.8) + 32 (gas phase)

State Newton's second law of motion. Define net force. In what units is it expressed?

F=ma net force=sum of all forces that act on an object Force is measured in newtons, 1N=1kg(m/s²)

For 6 seconds, you push a 120kg crate along a frictionless horizontal surface w a constant force of 60N parallel to the surface. If the crate was initially at rest, what will its velocity be at the end of this 6 second interval?

F=ma → 60N=(120kg)(a) → a= .5m/s² Next, use vf= v₀ + at → vf= 0 + (.5)(6sec) → vf=3m/s (Force)

Most common diatomic elements:

H2(g) N2(g) F2(g) O2(g) I2(s) Cl2(g) Br2(l) *Have No Fear Of Ice Cold Beer (the periodic table; electronic structure)

Floating objects in equilibrium on the surface:

Happens when Fbuoyancy =Fweight *forces in the y direction cancel out The fraction of the objects volume that's submerged is the same as the ratio of the object's density to the fluids density. This is given by: Vsubmerged/Vobject = 𝝆object/𝝆fluid (fluids)

An object of mass 50kg moves w a constant velocity of magnitude of 1000 m/s. What is the net force on this object?

If an object is moving at a constant velocity, then the net force it feels must be zero. Additionally, since the net force is zero, its acceleration is zero (Force)

When energy is added to a substance, that energy can be used to do one of two physical things. What are they?

Increase the temperature (increase the KE) or cause a phase change (increase the PE)

What three geometric family names are associated w each type of hybridized orbitals?

Linear= sp Trigonal planar= sp² Tetrahedral= sp³

Do magnetic forces do work?

No! Bc the magnetic force a charge feels is always perpendicular to the velocity of the charge, magnetic forces do no work. Recall that if a force, F, is perpendicular to the displacement, d, of an object, then this force does zero work bc W=Fdcosθ and cos(90)=0, so W=0 *since magnetic forces never do work, they can never change the KE of a particle. Thus, KE is constant. Magnetic forces cannot change the speed of a particle. All magnetic forces can do is make charged particles change their direction. They can't make them speed up or slow down. (Magnetism)

The amount of work done in a gravitational field is _______.

PATH INDEPENDENT -gravity always acts downward. Thus, it does not matter what detour you take bc sideward motion perpendicular to the gravitational force involves no work -gravity is a conservative force -pushing an object at constant speed up a frictionless inclined plane involves the same amount of work as directly lifting the same object to the same height at constant speed -sliding down a frictionless inclined plane involves the same gravitational work as doing a free fall at the same height *lifting something straight up, you exert a greater force over a smaller distance. *moving something up a ramp, you exert a smaller force over a greater distance **either way, the work done by gravity is the same in both case (Work)

Gravitational potential energy when close to the earth:

PE=mgh -closer you are to earth= less PE, (less work can be done by gravity) -farther away from earth= more PE, (more work can be done by gravity) -when you pick an object up, displacement is moving opposite the force of gravity, so negative work is being done by gravity. Wg = -mgh. KE is transferred out of the object. KE is transferred into PE. So, ΔKE < 0 **If something is being moved away from earth, it is gaining gravitational PE and losing KE. Overall, its internal energy is decreasing. Negative work is being done. Non-spontaneous. -when you lower an object closer to the ground, displacement is moving the same direction as the force of gravity, so positive work is done by gravity. Wg = mgh. KE is transferred into the object. PE is transformed into KE. So, ΔKE > 0 **If something is falling toward earth, it is losing gravitational PE and gaining KE. Overall, its internal energy is increasing. Positive work being done. Spontaneous. SUMMARY: when an objects at ground level, all energy is KE. When an object is at max height, all energy is PE. When an object is somewhere in between these two heights, it has some KE and some PE -So, the change in gravitational PE is defined to be the opposite of the work done by the gravitational force. This is expressed as: ΔPE = -Wgravity. *in other words, the ΔPE and Wg always have opposite signs If ΔPE is -, then Wg is + (object moving toward earth, spontaneous) If ΔPE is +, then Wg is - (object moving away from earth, non-spontaneous) -energy is never created or destroyed, (ΔEtotal = 0), it just converts from one form into another. For ex, when you jump out of an airplane, the earth is giving you KE. Converting your PE into KE. -spontaneous changes in the system occur when ΔPE < 0 -only CHANGES in potential energy, ΔPE, are meaningful and important. For ex, ΔPE is the same whether a 1kg object goes from 5m to 0m, or from 7m to 2m ΔPE= (1)(10)(0) - (1)(10)(5) → -50J ΔPE (1)(10(2) - (1)(10)(7) → -50J (energy of point object systems)

element Ag

Silver

What will happen to the gravitational force between two objects if the distance between them doubles? What if the distance is cut in half?

Since gravitational force obeys an inverse square law, Fgrav= G Mm/r², if r increases by a factor of 2, then Fgrav will decrease by a factor of 2²=4. If r decreases by a factor of 2, then Fgrav will increase by a factor of 2²=4 (Force)

A car whose mass is 2000kg is traveling at a velocity of 15m/s east. What is its momentum?

Since p=mv, p=(2000kg)(15m/s) → p=30,000 kgᐧm/s, if we call "east" the positive direction. (Equilibrium)

A friend is pushing you on a merry-go-round faster and faster. Eventually, it goes so fast that you fall off. Which way does your body move when falling off?

Tangent to the circle. When the force of static friction is finally exhausted and you fall off the merry-go-round, you no longer experience centripetal force. You will move the direction of the tangential velocity (Force)

The phase of a substance depends on what two properties besides intermolecular forces?

Temperature and pressure

Temperature (gases):

Temperature is a measure of the amount of internal kinetic energy that molecules have. The average kinetic energy of the molecules of a substance directly affect its state/phase (whether it's a solid, liquid, or gas). As KE increases, entropy increases Temperature can be expressed in F, C, or K. When using the ideal gas law, temp must ALWAYS be in kelvin (this is necessary to prevent negative values). *Converting from C to K, K = C + 273 *Converting from C to F, F = (C)(1.8) + 32 (gas phase)

If the plates of a capacitor were touching during the charging process, what would happen?

The capacitor would discharge almost immediately, since the transferred electrons would have a direct route back to the positive plate. All the PEelectric that had been stored would be lost in an instant, without any useful work being done by the stored energy. *this is why dielectrics are necessary! The plates cannot be touching. (Circuit Elements)

If you are given a Temp vs q graph, what do we know?

The slope of the T vs q graph is the specific heat, c (gas phase)

Real image:

To the observer, the image appears in front of the mirror (in real space) or in front of the lens (on opposite side as the object) *real images are INVERTED, can be cast on a screen *always has a +i *Converging (convex lens and concave mirror) can create both real, inverted and virtual, erect images *Diverging (concave lens and convex mirror) only create virtual, erect images (geometrical optics)

Units of potential:

Volt, V

The density of ice is 920 kg/m³, and the density of seawater is 1025 kg/m³. Approximately, what percentage of an iceberg floats above the surface of the ocean?

Vsubmerged/Vobject = 𝝆object/𝝆fluid → Vsubmerged/Vobject = 920/1025 → approximately 900/1000 → 9/10 → 90% submerged *Answer: 10% floats (fluids)

Standing wave on a rope (both ends fixed/nodes):

Waves on a rope= transverse wave. normally if you just have a wave w no boundaries, there is no preference for wavelength or frequency. Anything is equally probable. However, if you confine a wave to have boundaries, the wave will reflect once it hits the end and overlap onto itself. This can create standing waves. These waves have preferred wavelength and frequency. -node=point where there's no oscillation -antinode= point where there's maximum oscillation -the distance between any two consecutive nodes is always ½ the wavelength the standing-wave wavelength is given by: 1) ƛ=2L/n, where L is the length of the rope, and n is the harmonic number 2) ƛ=ƛfundamental/n, if we know the fundamental wavelength we can calculate all other harmonic wavelengths the standing wave frequency is given by: 1) f=nv/2L 2) f=(n)(fundamental frequency), if we know the fundamental frequency we can calculate all other frequencies *note: v=λf → f=v/λ and λ=2L/n, plugging λ equation into wave equation, you get f=nv/2L (periodic motion)

State the work-energy theorem

Wtotal=∆KE

What does a hydraulic jack do?

a hydraulic jack utilizes Pascal's Law to decrease the force necessary to support or lift an object

Lens:

a lens is a thin piece of clear glass that forms an image of an object by refracting light. Two types of lenses: 1) converging lens (convex lens)= thicker in the middle than they are at the ends -convex lenses are the same as concave mirrors (both are converging), except for: *real images are on the opposite side of the lens as the object. Because light travels through the lens and can focus on a screen behind the lens. *Virtual images are on the same side of the lens as the object. Because light can't focus in front of a lens and be cast on a screen. 2) diverging lens (concave lens)= thinner in the middle than they are at the ends -concave lenses are the same as convex mirrors (both are diverging), except for: *The virtual images formed by the lens is on the same side of the lens as the object. Because light can't focus in front of a lens and be cast on a screen. (geometrical optics)

Ohm's Law:

a material is said to obey Ohm's law if its resistance, R remains constant as the voltage is varied. Expressed by: V=IR, where V is the voltage, I is the current, and R is the resistance *this is the same as the equation for calculating resistance (Circuit Elements)

Density (fluids):

a measure of how condensed a substance is, mass/volume. Expressed by: 𝝆 = m/V *density has units of kg/m^3 or g/cm^3 -the density of liquid water is, 𝝆 = 1g/mL = 1g/cm^3 = 1kg/L = 1000 kg/m^3 (for conversion, 1kg = 1000g, 1L = 1000mL, 1^3m^3 = 100^3cm^3, see notes 4B) (fluids)

Universal indicator:

a pH indicator made of a solution of several compounds that exhibits several smooth color changes over a wide range pH values to indicate the acidity or alkalinity of solutions. The universal indicator is composed of methyl orange, methyl red, phenolphthalein, bromothymol blue, and several other indicators Universal indicator + a clear sample solution, if the solution turns: Red, your sample is very acidic Orange, your sample is acidic Yellow, your sample is weakly acidic Green, your sample is neutral Blue, your sample is basic Purple, your sample is very basic *additionally, indicators are used in acid-base titrations. The color change occurs when you reach the endpoint (molecular structure and absorption spectra)

Simple harmonic motion:

a special type of periodic motion or oscillation motion where the restoring force is directly proportional to the displacement and acts in the direction opposite to that of displacement. And the frequency and period of oscillations are independent of the amplitude. Any simple harmonic motion can be expressed by: x=Asin(ωt) or x=Asin(2𝝅ft) or x=Asin(2𝝅t/T) *use sin when starting from equilibrium position, x=0. Use cos if not starting from equil. Examples of simple harmonic motion: oscillating spring, pendulum, things going around a circle at a constant speed. With simple harmonic motion, when you plot displacement, x, vs time, t, you get a sinusoidal function, (the graph of sin!) simple harmonic motion requires: 1)dynamics condition: restoring force is directly proportional to displacement from equilibrium, (x=0), and points towards the equilibrium point 2)kinematics condition: frequency and period are independent of the amplitude of oscillations (periodic motion)

Oxidized metal cations:

alkali and alkaline earth metals tend to lose one to two electrons, respectively, becoming oxidized metal cations (the periodic table; electronic structure)

Describe each kind of nuclear decay

alpha decay: nucleus emits a helium nucleus (2p+ and 2n) β-: neutron is converted into a p+ and an e- (which is emitted) β+: a p+ converts into a neutron and a positron, e+ (which is emitted) electron capture: p+ in the nucleus captures an inner-shell e- and uses it to convert a p+ to a n gamma: excited nucleus drops to lower energy state by emitting a gamma photon

Inelastic collisions:

an inelastic collision is one in which total momentum is conserved, but total KE is not. KE is lost during the inelastic collision. If you drop a ball and the ball does not bounce back to its original height, that's an inelastic collision. The ball lost some KE. -Most collisions in everyday life are inelastic to varying degrees. Everyday collisions result in the loss of energy due to heat, sound, deformation, etc. So, most collisions we experience are not elastic. -perfectly inelastic collisions are a subtype of inelastic collisions. When objects stick together, they lose the most KE (Equilibrium)

Ligand:

an ion or molecule attached to a metal atom. Any ion or molecule with a pair of nonbonding electrons can be a ligand. (the periodic table; electronic structure)

Conservation of total mechanical energy:

an object's total mechanical energy, E, is the sum of the object's PE and KE. -Conservation of total mechanical energy= when the only forces acting on an object during its motion are conservative (for ex, no friction), then the object's total mechanical energy will remain the same throughout the motion. The KE is converted to PE or vice-versa. This is expressed by: ΔKE = -ΔPE or ΔKE + ΔPE = 0 or KE₀ + PE₀ = KEf + PEf -so, the total amount of energy before = the total amount of energy after. For ex, gravitational PE is converted to KE as an object falls, but the total amount of energy stays the same -one of the most useful things about solving problems using the conservation of mechanical energy is that KE, PE and E are all scalars. So, you don't have to worry about x and y components. *remember, one of the thermodynamic properties of a system is its internal energy, E, which is the sum of the KE and PE's of the particles that form the system (energy of point object systems)

Bernoulli (Venturi) effect:

as the speed of a moving ideal fluid (liquid or gas) increases, the pressure within the fluid decreases. -occurs in ideal fluid flow when y1 = y2, (two points in a pipe are at the same height). When this happens, the bernoulli equation becomes: P₁ + ½ ⍴v₁² = P₂ + ½ ⍴v₂² *in a pipe, if point 1 has a large area, and point 2 has a small area, but both points are at the same height, then: -from the continuity equation, f=Av, we know that the speed increases as the cross-sectional area of the pipe decreases -additionally, the pressure is lower where the flow speed is greater. This is known as the Bernoulli (Venturi) effect. *hydrodynamics (fluids)

Beat frequencies:

beats occur when two waves coexist at different frequencies (have diff periods). Bc the frequencies don't match, sometimes the waves are in phase (constructive interference) and sometimes they're out of phase (destructive interference). You will actually hear sound getting louder and quieter. One beat is the transition from quiet → to loud → to quiet. The frequency at which the beats are heard (the beat frequency) is equal to the difference between the frequencies of the two original sound waves. fbeat= |f1 - f2| (sound)

Mirror curvature can be _________.

concave or convex (geometrical optics)

Supersaturated solution:

concentration > solubility, additional solute causes excess to PRECIPITATE. For ex, you have water w excess NaCl. If you heat this up (causing it to dissociate), then allow it to slowly cool. If you add more solute, it will cause ALL the excess NaCl to precipitate (come out of solution). This is called a catastrophic precipitation. Liquid → Solid, happens very quickly. The more supersaturated the solution is, the more precipitation you will get (gas phase)

Exponential Decay:

A quantity is subject to exponential decay (decreases exponentially) if it decreases at a rate proportional to its current value. (atomic nucleus)

What is the oxidizing agent? What is the reducing agent? C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H2O(l)

-The oxygen (O₂) is being reduced, so it is the oxidizing agent. -The glucose (C₆H₁₂O₆) is being oxidized, so it is the reducing agent. (electrochemistry)

Electrostatic charge vs effective nuclear charge:

-Electrons are held in an atom or ion by the electrostatic attraction (Felectrostatic) between the positively charged nucleus and the negatively charged electrons. -In multi-electron species, the electrons do not experience the full positive charge of the nucleus due to shielding by electrons which lie between the electron of interest and the nucleus. The amount of positive charge that actually acts on an electron is called the effective nuclear charge, Zeffective. (periodic table; group and row)

Molarity vs Molality:

-Molarity, M=mol solute/L solution -Molality, m=mol of solute/kg solvent *both molarity and molality measure the concentration of solutes in a solvent

What conditions are indicated by the letters STP?

1 atm and 0C

Times tables, 12:

12x1 = 12 12x2 = 24 12x3 = 36 12x4 = 48 12x5 = 60 12x6 = 72 12x7 = 84 12x8 = 96 12x9 = 108 12x10 = 120 12x11 = 132 12x12 = 144 12x13 = 156 12x14 = 168 12x15 = 180 *And 12²=144

Times tables, 13

13x1 = 13 13x2 = 26 13x3 = 39 13x4 = 52 13x5 = 65 13x6 = 78 13x7 = 91 13x8 = 104 13x9 = 117 13x10 = 130 13x11 = 143 13x12 = 156 13x13 = 169 13x14 = 182 13x15 = 195 *And 13²=169

Times tables, 15:

15x1 = 15 15x2 = 30 15x3 = 45 15x4 = 60 15x5 = 75 15x6 = 90 15x7 = 105 15x8 = 120 15x9 = 135 15x10 = 150 15x11 = 165 15x12 = 180 15x13 = 195 15x14 = 210 15x15 = 225 *And 15²=225

A batter strikes a pitched baseball (mass=.15kg) that was moving horizontally at 40m/s, and it leaves his bat moving at a speed of 50m/s directly back toward the pitcher. The bat was in contact w the baseball for 15ms. A) what's the baseballs change in momentum? B) what's the impulse of the force exerted by the batter? C) what's the magnitude of the average force exerted by the bat on the ball?

A) since we're dealing w momentum, which is a vector, we need to define which direction is positive and negative. Let's choose towards the pitcher as positive. This gives: p₀=mv₀ → (.15kg)(-40m/s) → -6kgᐧm/s = p₀ pf=mvf → (.15kg)(50m/s) → 7.5kgᐧm/s = pf *so the overall change in the baseball's momentum is: 7.5 - (-6) → 13.5 kgᐧm/s = Δp B) here, we are not told what the force is. The impulse-momentum theorem tells us that the impulse is equal to the change in momentum. Since Δp=13.5 kgᐧm/s, this is also the impulse of the force. So, 13.5 Nᐧs = J. C) Since we know J, we can use J=FΔt to find F. Thus, J=FΔt → F=J/Δt → 13.5Nᐧs/.015s → 900N = F (Equilibrium)

Determine the oxidation state of the atoms in each of the following molecules NO₃⁻ HNO₂ O₂ SF₄

A)O has an oxidation state of -2. N has an oxidation state of +5 B)H has an oxidation state of +1. O has an oxidation state of -2. N has an oxidation state of +3 C)each O atom has an oxidation state of 0 D)F has an oxidation state of -1. S has an oxidation state of +4 (electrochemistry)

Acidic oxide:

Also called acid anhydrides. They are mostly oxides of non-metals, and they dissolve in water to form acids. Thus, CO2 dissolves in water to give carbonic acid (H2CO3), and NO2 gives a mixture of nitrous and nitric acids (HNO2 and HNO3) (the periodic table; electronic structure)

Fundamental frequency:

Also called the first harmonic number. It is the lowest frequency that a standing wave can produce. It is only ½ of a wavelength. Where, ƛ=2L. It's composed of two nodes, one at each end, but no nodes in the middle. (periodic motion)

Current is measured in ______.

Amps *coulombs of charge passing a certain point per second 1A = 1C/s *Note: we know that 1C is a lot of charge. Thus, 1A is a lot of current! 0.01A will produce slight tingling. 0.2A will stop your heart. (Circuit Elements)

While in water, an object's APPARENT WEIGHT is less bc of the ________.

Buoyant force pushing upwards wapparent = w - Fbuoyancy (fluids)

Virtual images have orientations that are always ________.

Erect, Upright (geometrical optics)

State Newton's Law of Gravitation

Every pair of objects exerts a gravitational attraction on each other, w strength F=GMm/r², where G is the universal gravitational constant, m₁ and m₂ are the masses, and r is the (center of mass to center of mass) distance between the objects

Van't Hoff factor:

Expressed as i, it tells you the number of particles produced in solution per mole of substance. For ex: *when C₆H₁₂O₆ is put into water, it does not dissociate. It is a nonelectrolyte. (note, this is glucose!) C₆H₁₂O₆ + H₂O → C₆H₁₂O₆ + H₂O, i=1 *when NaCl is put into water, it dissociates into two particles. Since it dissociates completely, it is a strong electrolyte. NaCl + H₂O → Na+ + Cl-, i=2 *when Ca(NO₃)₂ is put into water, it dissociates into three particles. Since it dissociates completely, it is a strong electrolyte. Ca(NO₃)₂ + H₂O → Ca²⁺ + 2NO₃⁻, i=3 (gas phase)

Of the following, which gas would behave most like an ideal gas if all were at the same temp and pressure? A)O2(g) B)CH4(g) C)Ar(g) D)Cl2(g)

Ideal gases have no volume and no intermolecular interactions. The gas from this list that will behave the most like an ideal gas will be the one w the smallest volume. O2, CH4, and Cl2 are all polyatomic molecules that occupy more space than atomic argon. So, argon takes up the least volume; it is the most ideal. (gas phase)

Of the following, which gas would behave the most like an ideal gas if all were at the same temp and pressure? A)H2O(g) B)CH4(g) C)HF(g) D)NH3(g)

Ideal gases have no volume and no intermolecular interactions. The gas from this list that will behave the most like an ideal gas will be the one w the weakest intermolecular forces. H2O, HF, and NH3 all experience H-bonding, while CH4 only experiences weak dispersion forces. So, CH4 is the most ideal. (gas phase)

If the angle of incidence is zero degrees, what happens?

If the angle of incidence is zero degrees (the incident ray is perpendicular to the plane), then the light passes undeviated. Hence the angle of refraction will be zero. And the angle of the reflected ray will also be zero (geometrical optics)

Discharge of a capacitor:

If you transfer electrons from one plate of a capacitor to the other, you do work against the electric field of the capacitor, and, as a result, you store PEelectric. To recapture this stored electric energy, you let the electrons go back to their original plate, effectively discharging the capacitor. The movement of electrons can be used in a productive manner by providing a path for them and placing some electrical devices along the way. As a result, the electrons that return to the plate end up passing through, say, a light bulb, and the current causes the bulb to light. *the energy stored in a capacitor can be used to do useful work *during the discharge of a capacitor, the capacitor acts as a battery and drives current flow, which decreases w time as the capacitor discharges. (Circuit Elements)

Indicator:

Indicators are substances whose solutions change color due to changes in pH. These are called acid-base indicators. They are usually weak acids or bases, but their conjugate base or acid forms have different colors due to differences in their absorption spectra. (molecular structure and absorption spectra)

Define inertia. How it is measured? State Newton's Law of Inertia

Inertia is an objects natural resistance to change in its state of motion. For translational motion, inertia depends on mass, in kg. Fnet=0, v=constant For rotational motion, inertia depends on mass, in kg, and distance from the center of rotation, in m. Torquenet=0, v=constant

When you toss something straight up and it comes down to where it started, there is symmetry. Initial velocity and final velocity are _______.

Initial velocity and final velocity in y direction are equal and opposite. time spent going up = time spent going down Total displacement is zero The initial velocity in y direction and acceleration are opposite in sign (acceleration is just -g) (translational motion)

How does a projectile's horizontal velocity change during its flight if air resistance is ignored?

It doesn't (bc there is no horizontal acceleration, only the vertical acceleration due to gravity)

Define lens power. In what units is it measured? What is the overall power of a combination of lenses?

P=1/f, where f=focal length in meters, and power has units of diopters, D, where 1D=1m⁻¹ Ptotal=sum of individual powers

If a force does 100J of work in 20 seconds, then work is being done at a rate of:

P=W/t → 100J/20s → 5W = P or 5J/s (Work)

A force of magnitude 40N pushes on an object of mass 8kg through a displacement of 5m for 10sec. What's the power provided by this force?

P=W/t → P=Fd/t → (40N)(5m)/10s → 20W = P (Work)

Define pressure. In what units is it measured?

P=force/area. It is measured in pascals (Pa), where 1Pa=1N/m²

If two moles of helium at 27C fill a 3L balloon, what is the pressure?

PV=nRT → P=nRT/V → P= (2mol)(.08 Lᐧatm/Kᐧ mol)(300K) // 3L → 16atm *If temp is -50C to +50C, close enough to STP (0C), can still treat as an ideal gas. (gas phase)

A 2mol sample of He initially at 1atm and 27C has its temp doubled and its volume halved. What is the final pressure of the gas?

PV=nRT, here n and R are constant, so we just have PV∝T → P∝T/V → P∝ 2/(1/2) → P∝4 and since the sample was initially at 1atm, we have (4)(1atm) → 4atm (gas phase)

element Pd

Palladium

Solution:

Particles < 2nm. Involves aqueous solutions. Things are mixed at the molecular level and will always stay mixed. When you use the term dissolve, you are making a solution. For ex, NaCl + H2O → Na+ + Cl-

Describe the speed of sound through different medium:

Speed of sound in solids > liquids > gases *sound travels the fastest in solids bc solids are the most stiff *speed of sound in stiff objects > compressible objects *speed of sound in less dense objects > more dense objects (even though gases are less dense than solids, sound still travels slower in them bc they are too compressible) *speed of sound in hot objects > cold objects REMEMBER: when a wave passes into another medium, its speed changes, but its frequency does not. In other words, frequency is constant between media. If a wave is traveling from air into water, (a more dense medium), once the wave hits the water it will develop a larger wavelength and thus a larger velocity. The frequency, however, is the same. The rate in = rate out. (sound)

What element can you substitute for oxygen in a given chemical reaction and still keep the same chemical reactivity?

Sulfur *this is a high yield question! Oxygen and Sulfur are chemically similar and thus can be substituted for eachother (the periodic table; electronic structure)

Charles' Law:

T is directly proportional to V (constant n, P) T ∝ V or V1/T1 = V2/T2 Charles law extrapolates to absolute zero, where volume also goes to zero (this is only an extrapolation CONSTANT PRESSURE (gas phase)

Units of magnetic field:

Tesla, T (translational motion)

What information is required to calculate the amount of an element that can be produced in an electrolytic cell?

The current (in amps), the amount of time the current is applied, the number of moles of electrons transferred per mole of the element formed (given by the half-reaction), and Faraday's constant It=nF

Kinetic energy:

The energy an object has due to its motion. Energy is the ability to do work. Kinetic energy is expressed by: KE = 1/2mv² -the unit for KE is the J, or kgᐧm/s² -KE is a scalar quantity. Only cares about speed of an object, not the direction. -at the same speed, the larger mass has the larger KE -when you double the mass, you double the KE -at the same mass, the higher speed has the larger KE -when you double the speed, you quadruple the KE -speed is more important than mass for the KE bc speed is squared (energy of point object systems)

How is Coulomb's law similar to Newton's Law of Gravitation?

They are both inverse square laws

When you add increasing amounts of solute, what happens to the vapor pressure?

Vapor pressure is a colligative property. When you add more solute, VAPOR PRESSURE DEPRESSION occurs. Solute molecules are attached to solvent molecules and act as "anchors." As a result, more energy is required for a liquid to enter the gas phase, thus vapor pressure decreases. For ex, salted water for boiling spaghetti has a higher bp, lower Pvap than normal water. Pvap depression, ΔP = (Xsolute)(P°solvent) *ΔP gives you the change in vapor pressure, Xsolute is the mole fraction of the solute, P°solvent is the Pvap of the pure solvent alone. When calculating the mole fraction of the solute, make sure you take into account van't hoff (1mol of NaCl in solution is actually 2mols of particles) **wants to stay a liquid (gas phase)

Index of refraction:

When light travels through a medium other than a vacuum, its speed is less than c. Every medium has an index of refraction, expressed by: Index of refraction= speed of light in vacuum/speed of light in medium or n=c/v, where n is the index of refraction for the medium, and v is the speed of light traveling in that medium *the index of refraction of vacuum and for air, n=1 *n has no units and n is never less than 1 *the greater the value of n for a medium, the slower light travels through the medium *diamond has a particularly high index of refraction, n=2.4 (geometrical optics)

Pitot tube:

a flow measurement device used to measure fluid flow velocity. (fluids)

Electron volt (eV):

an electron moving through a potential difference of 1V experiences a KE change of 1.6x10^-19 J = 1eV ΔPE=qΔɸ --> ΔPE=(-1.6x10^-19)(1) --> ΔPE=-1.6x10^-19 J So, ΔKE=1.6x10^-19 J = 1eV (Electrostatics)

Resistivity:

expresses the resistance in terms of a materials intrinsic properties. Expressed by: R=⍴ L/A, where R is the resistance, ⍴ is the resistivity of the material, L is the length of the wire, and A is the cross sectional area of the wire *resistivity is the inverse of conductivity *greater resistivity means greater resistance of the material *conductors, like metals, have very low intrinsic resistivity *insulators, like rubber, have very high intrinsic resistivity **every material has its own resistivity *To make a wire of low resistance, select a material that has low resistivity, keep the wire shor, and keep the diameter of the wire large *extension cords are made really thick to keep the resistance down, so it doesn't heat up and cause a fire (Circuit Elements)

A galvanic cell is set to operate at standard conditions. If one electrode is made of magnesium and the other is made of copper, then the magnesium electrode will serve as the? Mg²⁺ + 2e- → Mg, has a standard potential of -2.36, (E=2.36) Cu²⁺ + 2e- → Cu, has a standard potential of 0.34, (E=0.34)

magnesium has a more negative reduction potential, and will thus be a good reducing agent. So, magnesium will be the anode and will be the site of oxidation (electrochemistry)

Physical changes vs chemical changes:

matter can undergo both physical and chemical changes -physical changes= solid → liquid → gas, involves intermolecular forces -chemical changes= change in chemical bonding (breaking a covalent bond), involves intramolecular forces (gas phase)

Viscosity:

the force of cohesion between molecules in a fluid; think of it as internal friction for fluids. For ex, maple syrup is more viscous than water, and there's more resistance to the flow of maple syrup than to the flow of water (fluids)

Diffraction grating:

took young's double slit experiment and added multiple slits to a plate instead of just two slits. This is beneficial bc you get definite bands of light and dark. You get no intermediate-brightness bands (this makes it easier to solve problems in the laboratory). This occurs bc if the path difference deviates even slightly from a whole number of wavelengths, you will get destructive interference. *diffraction= light spreads out after passing through the slit, instead of going in a straight line *diffraction grating= a slab w many slits close together *the equation for a diffraction grating is the same as the double slit experiment, dsinθ=mƛ *bright bands occur at m= 0, +/-1, +/-2, etc *dark bands occur at m= +/-0.5, +/-1.5, +/-2.5, etc (light/electromagnetic radiation)

Distance:

total length traveled; path taken matters; scalar quantity -distance gives you the total distance traveled. You cannot have a negative distance. -units are in meters Ex, if a sprinter runs 400m around a circular track and returns to her starting point, then her total distance is 400m. Her displacement is 0. (translational motion)

Pauli exclusion principle:

two e- in the same orbital must be of diff spins. For ex, two e- in the px orbital, one will be spin up and one will be spin down (electronic structure)

List common 2-D shapes and how to calculate their perimeter and area:

1) rectangle perimeter/circumference: P=2(l+w) area: A=lw 2) square perimeter/circumference: P=4s area: A=s² 3) triangle perimeter/circumference: P=a+b+c area: A=1/2bh 4) circle perimeter/circumference: C=π(diameter) = 2π r area: A=π r²

A block of 5kg, with a coefficient of static friction of 0.3, is sitting still on a horizontal surface. If 8N of force are applied, will the block move?

Since its not moving in the y direction, Fn=Fw Ffs,max = µsFn→ Ffs = (.3)(Fw) → Ffs = (.3)(5kg)(10) → 15N *here, the block can withstand 15N of force (15N is the maximum force of static friction). You must apply 15N of force to get the block moving. So, only applying 8N of force will result in no movement of the block. (Force)

Newton's 3rd law:

When two objects interact, they exert equal and opposite forces on each other. Every action has an equal and opposite reaction F1 on 2 = - F2 on 1 For ex, when on an airplane and a bug hits the windshield. The bug and plane exert the same forces on each other. The bug explodes and dies while the plane is fine bc they have very diff masses. A huge acceleration is placed on the bug causing it to die. A tiny/insignificant acceleration is placed on the plane, causing no issues for the plane. Fbug on window = ma, tiny mass and large acceleration Fwindow on bug = ma, large mass and tiny acceleration **Rocket propulsion follows Newton's Third Law. To get a rocket off the launch pad, create a chemical reaction that shoots gas and particles out one end of the rocket and the rocket will go the other way. This is why rockets work even in the vacuum of space. (Force)

Projectile motion:

projectiles are free-falling bodies ACCELERATION: -horizontal component of acceleration: ax= 0 -vertical component of acceleration: ay= -10m/s² = -g *since acceleration is constant, use the Big Five kinematic equations! VELOCITY: -horizontal component of velocity: v₀x= vx, horizontal component of velocity is constant -vertical component of velocity: vy= v₀y + at *vy = 0 at top of trajectory DISPLACEMENT -horizontal component of displacement: x= v₀xt -vertical component of displacement: y= v₀yt + ½ at² (translational motion)