Exam 2: Chapter 3, 4, + 5 (3/8/18)
What is the formula mass of CO₂? Na₂O?
(12.01) + 2(16.00) = 44.01 amu 2(22.99) + 16.00 = 61.98 amu
Heisenberg's Equation for the Uncertainty Principle
(∆x)(m∆v) ≥ h/4π The product of ∆x and m∆v must be greater than or equal to a finite number
(+/-) is used when an element loses an electron.
+
Rydberg Constant for Hydrogen
- 2.18 x 10⁻¹⁸ J
Aufbau Principle
-"Building up" -A pattern of orbital filling where 2 electrons with opposing spins can be in each orbital
de Broglie Model
-1924 -Wave nature of electrons, seen most clearly in diffraction -Explains the existence of stationary states and prevents electrons from crashing into the nucleus -The wave nature of the electron is the inherent property of individual electrons -λ = h/mv
Schrödinger's Cat
-1935 thought experiment -Cat is put in a steel chamber that contains radioactive atoms -Upon emission of an energetic particle by one of the radioactive atoms, causing a hammer to break a flask of hydrocyanic acid (a poison). If flask breaks, the poison is released, and the cat dies -If the steel chamber is closed, the whole system remains unobserved, and the radioactive atom is in a state where it has both emitted and note emitted the particle (with equal probability); therefore the cat is both dead and undead. When the chamber is opened, it forces it into one state
Planck's Constant
-6.626 x 10⁻³⁴ J -Symbol: h
Electron Spin
-A fundamental property of electrons that affects the number of electrons allowed in any one orbital -Two possible orientations: either with the magnetic field or against it -Pauli exclusion principle
Molecular Model
-A more accurate and complete way to specify a compound -Can be ball-and-stick or space-filling
Periodic Properties
-A property that is generally predictable based on an element's position within the periodic table -Quantum mechanical theory explains the electronic structure of atoms, therefore determines the properties of those atoms
Atomic Radius
-A set of average bonding radii determined from measurements on a large number of elements and compounds -Radius of an atom when it is bonded to another atom -Always smaller than van der Waals
Probability Distribution Map
-A statistical map that shows where an electron is likely to be found under a given set of conditions -Considers electrons' indeterminacy, meaning it can only be described statistically
Electromagnetic Radiation
-A type of energy embodied in oscillating electric and magnetic fields -In a vacuum, travels at 3.00 x10⁸ m/s
Interference
-A wave interaction that results in them building each other up or canceling each other out depending on their alignment -Constructive or destructive
Ionic Compound Formulas
-Always contain positive and negative ions -The sum of the charges of the cations and anions must equal each other in a chemical formula -The formula reflects the smallest whole-number ratio of ions
The Angular Momentum Quantum Number
-An integer that determines the shape of the orbital -Possible values: any integer up to n-1, including 0 -Symbol: l
The Magnetic Quantum Number
-An integer that specifies the orientation of the orbital -Possible values: integers (including 0) -l to +l -Symbol: ml
Polyatomic Ion
-An ion composed of two or more atoms -Named the same way as binary, but the ion name is used whenever it occurs
Oxyanions
-Anions containing oxygen and another element -Name them according to the number of oxygen atoms in the ion -Ion with more oxygen atoms has the ending -ate; one with fewer ends in -ite -If there are more than two ions, use either hypo- or per-
Threshold Frequency Condition
-As the frequency of the light increases over the threshold frequency, the excess energy of the photon transfers to the electron in the form of kinetic energy -hv = ∅
Metallic Character
-As we move right, metallic character decreases -As we move down, metallic character increases -An atom or ion's metallic tendencies
Erwin Schrödinger
-Austrian physicist -1887 to 1961 -1935: paper that contained a thought experiment about a cat
Formula Unit
-Basic unit of an ionic compound -Not a molecule -Does not exist as a discrete entity, but rather as a part of a larger lattice
Ionic Bonds
-Bonds formed between metals and nonmetals -Metals have a tendency to lose electrons while nonmetals gain them -Metal becomes cation and nonmetal becomes anion -Form an ionic compound -Nondirectional and hold together an entire array of ions
Visible Light
-Can be seen with naked eye -Correspond to different wavelengths/frequencies -Violet (highest energy) to Red (lowest energy) -Can't damage biological molecules, but does affect sight -10⁻⁶ to 10⁻⁷
X-Rays
-Can pass through many substances that can block visible light -Can damage biological molecules and increase cancer risk -10⁻⁹ to 10⁻¹¹ nm
Ultraviolet Radiation (UV)
-Causes sunburn/tan -Not as damaging as Gamma and X-rays, but still can damage biological molecules and increases risk of cataracts, skin cancer, and premature wrinkles -10⁻⁷ to 10⁻⁹ nm
Organic Compounds
-Composed of carbon and hydrogen, and a few other elements including nitrogen, oxygen, and sulfur -Simplest organic compound is methane (CH₄) -Key element is carbon, which forms bonds with itself to form chain, branched, or ring structures -Simplest organic compounds are called hydrocarbons
Ionic Compound
-Composes a lattice (regular 3D array) in a solid state of altering anions and cations -Can be one that creates 1 type of ion or multiple types of ions
Hydrated Ionic Compounds
-Contain a specific number of water molecules associated with each formula unit -For example, in MgSO⁴(7H²O), the 7H²O associated with the formula unit are waters of hydration, which can be removed with heat -Named as other compounds except (#)hydrate is added at the end
Binary Compounds
-Contain two different elements -Naming: name of cation (metal) + base name of anion (nonmetal) + -ide
Covalent Bond
-Forms between nonmetals -Nonmetals have higher ionization energies, so they share electrons rather than transfer them -Form molecules and molecular compounds -Highly directional and hold one specific pair of atoms
Molecular Chemical Formula
-Gives the actual number of atoms of each element in a molecule of a compound -Always a whole number multiple of the empirical formula (keeps ratio) -Can be the same as empirical -Empirical formula x n i.e. hydrogen peroxide → H₂O₂
Infrared Radiation (IR)
-Heat-based radiation -Invisible to naked eye, but it can be seen on infrared sensors to see in the dark -10⁻³ to 10⁻⁶
Electromagnetic Spectrum
-Includes all the wavelengths of light -Ranges from 10⁻¹⁵ m (gamma rays) to 10⁵ m (radio waves) -Short wavelength/high frequencies on the right, long/low on the left
Chemical Formula
-Indicates the elements present in a compound and the relative number of atoms or ions of each -Subscript indicates the relative number of atoms of the element -List metallic first -Types: empirical, molecular, and structural
Penetration
-Inner electrons unable to shield the outer, and it penetrates 1s level -Experiences a greater nuclear charge and a lower energy
The Principal Quantum Number
-Integer that determines the overall size and energy of an orbital -Possible values: 1,2,3,... -For a hydrogen atom, En = - 2.18 x 10⁻¹⁸ J (1/n²) -Higher values of n = greater (less negative) energies -As n increases, spacing between levels becomes smaller -Symbol: n
What was different about Einstein's view of light?
-It was lumpy -Packets of light -A beam of light is not a wave propagating through space, but a shower of particles (photons), each with energy hv
Metalloids
-Lie along the zigzag that divides metals and nonmetals -Several are classified as semiconductors (temperature-dependent conductivity) -Used a lot in technology
Nonmetals
-Lie on the upper right side of the periodic table -Varied properties, but as a whole tend to be poor conductors -Tend to gain electrons during chemical changes to gain noble gas configuration
Radio Waves
-Longest wavelengths -Used to transmit AM/FM radio, cell phone, TV, and other communication signals
Metals
-Lower left side and middle of periodic table -Good conductors of heat and electricity -Can be pounded into flat sheets (malleable) -Can be drawn into wires (ductility) -Often shiny -They tend to lose electrons when they undergo chemical changes to attain noble gas configuration (transition metals do this, but generally don't attain noble gas configuration)
Elemental Organization by Dmitri Mendeleev (1834-1907)
-Modern periodic table -Listed according to increasing mass and saw repeating patterns; similar properties fell in vertical columns
Bonding Atomic Radius (Covalent Radius)
-Nonmetals: ½ the distance between two of the atoms bonded together -Metals: ½ the distance between two of the atoms next to each other in a crystal of the metal
Pauli Exclusion Principle
-One consequence of electron spin that means a maximum of two electrons can occupy any given orbital, and the two electrons occupying the same orbital must have opposite spin -No two electrons in an atom can have the same four quantum numbers
Bohr's Model
-Orbits exist only at specific, fixed distances from the nucleus -Orbit is fixed and quantized -Stationary states → mechanically explainable stability -No radiation is emitted by an electron orbiting the nucleus in a stationary state, only when an electron is excited and jumps -Electrons are never absorbed between states -The photon energy emitted in a transition is the difference between the two stationary states
Alkaline Earth Metals (Group 2A)
-Outer electron configuration ns² (2 electrons beyond noble gas configuration) -Form 2+ ions after chemical changes
Halogens (Group 7A)
-Outer electron configuration ns²np⁵ (1 electrons away from noble gas configuration) -Form 1- ions after chemical changes
Alkali Metals (Group 1A)
-Outer electron configuration ns¹ (1 electron beyond noble has configuration) -Form 1+ ions after chemical changes
Rydberg's Equation
-Predicts the wavelengths of hydrogen emission spectrum -1/λ = R(1/m²-1/n²) R = Rydberg's Constant = 1.097 x 10⁷ m⁻¹ m/n are integers
Complimentary Properties
-Properties that exclude one another -The more we know about one, the less we know about the other
Microwaves
-Radar and microwave ovens -Efficiently absorbed by water, and can heat substances containing water -10⁻¹ to 10⁻³
Atomic Mass
-Represented by "A" -Number of protons + number of neutrons -An average mass of an element
Atomic Number
-Represented by "Z" -Number of protons an element has
Ball-and-Stick Molecular Model
-Represents atoms as balls and chemical bonds as sticks -How the two connect represent a molecule's shape -Balls are typically color-coded to specific elements
Gamma Rays (γ)
-Shortest wavelength -Highest frequency -Produced by the sun, other stars, and certain unstable atomic nuclei on Earth -Excessive exposure is dangerous to humans because it can damage biological molecules -10⁻¹¹ to 10⁻¹⁵ nm
Electron Configuration
-Shows the particular orbitals that electrons occupy for that atom -Example: H 1s¹ s = orbital ¹ = Number of electrons in orbital
Orbital Diagram
-Similar to an electron configuration, but it symbolizes the electron as an arrow and the orbital as a box -Arrow direction indicates orientation of electron spin (+½ = ↑; −½ = ↓)
Absorption Spectrum
-Similar to emission spectrum, but it has dark lines on a bright background -More commonly used for identification purposes -White light passed through a sample and missing wavelengths are observed -Plot the intensity of absorption as a function of wavelength
The Spin Quantum Number
-Specifies the orientation of the spin of the electron, a fundamental property of an electron -Possible values: spin up → +½; spin down → ⁻½ -Symbol: ms
What is work function?
-Symbol: Φ -The minimum amount of energy required to induce photoemission of electrons from a metal surface -The value of Φ depends on the metal
Mass Percent Composition
-That element's percentage of the compound's total mass -Acts as a conversion factor Mass % of X = (mass of X in 1 mol of compound/mass of 1 mol of the compound) x 100%
Formula Mass
-The average mass of a molecule of a compound (a formula unit) -The sum of the atomic mass of all the atoms in the chemical formula a.k.a molecular weight; molecular mass Formula mass = (number of atoms in 1st element x atomic mass of 1st element) + (number of atoms in 2nd element x atomic mass of 2nd element)
Wavelength
-The distance between adjacent crests -Measured in units such as meters/micrometers/nanometers -Symbol: λ
Lattice Energy
-The energy associated with the formation of crystalline lattice of alternating cations and anions from the gaseous ions -Formation of an ionic compound is an exothermic process -The transfer of an electron absorbs energy, but energy is emitted when the lattice forms
Electron Affinity (EA)
-The energy change associated with the gaining of an electron by the atom in a gaseous state -Usually negative because an atom or ion usually releases energy when it gains an electron -Most groups do not exhibit any definite trend
Ionization Energy (IE)
-The energy required to remove an electron from the atom or ion in the gaseous state -Always positive because it is removing an electron (endothermic) -Energy to remove first electron is called the first ionization energy (IE₁)
When experiments were performed to look at the effect of light amplitude and frequency, what results were observed?
-The kinetic energy of photoelectrons increases with light frequency. -Electric current remains constant as light frequency increases. -Electric current increases with light amplitude. -The kinetic energy of photoelectrons remains constant as light amplitude increases.
Frequency
-The number of cycles that pass through a stationary point in a given period of time -Measured in cycle/s (s⁻¹) or Hz -Proportional to the speed the wave is traveling -Inversely proportional to λ -Symbol: v
Photoelectric Effect
-The observation that many metals emit electrons when light shines upon them -Energy transfers from light to an electron, which dislodges it -Light has threshold frequency, which means below it, no electrons are emitted from the metal -Intensity of light does not affect it, but frequency (wavelength) does -E = hv
Coulomb's Law
-The potential energy (E) of two charged particles depends on their charges (q₁ and q₂) and on their separation (r) -Potential energy is positive for interactions of the same sign, and negative for opposite signs -Magnitude depends on inversely on the separation between the charged particles E = (1/4πε₀)(q₁q₂/r)
Shielding
-The repulsion of one electron by another -Any one electron experiences both the positive charge of the nucleus and the negative charge of the other electrons -Inner electrons shield the outer electron of ions from the full nuclear charge
Emission Spectrum
-The series of bright lines separated by a prism -The es of a particular element is always the same
Empirical Formula Molar Mass
-The sum of the masses of all the atoms in an empirical formula -Molar mass (M) = empirical formula molar mass x n -n = M/empirical formula M
Combustion Analysis
-Unknown compound undergoes combustion in the presence of pure oxygen -When burned, all carbon is converted to CO₂ and all hydrogen to H₂O. Everything is then weighed -Numerical relationships between moles inherent in formulas are used to determine the amounts of C and H in the original sample -The difference is taken to find the mass of the other elements
Structural Chemical Formula
-Uses lines to represent covalent bonds and shows how atoms in a molecule are connected or bonded to each other -Can also be written to give a sense of the molecule's geometry i.e. hydrogen peroxide → H−O−O−H
Lewis Model
-Valence electrons represented as dots -Used to predict whether or not a stable molecule will be formed and what it will look like -Maximum 2 dots per side -Main group elements -Octet rule: stable configurations have 8 dots -Anion is written with brackets after electron transfer with the charger in the upper right hand corner outside the brackets
Heisenberg's Uncertainty Principle
-We can never both see the interference pattern and simultaneously determine which hole the electron goes through -We can never simultaneously observe both the wave nature and the particle nature of the electron (complimentary properties) -We cannot simultaneously measure its position and its velocity with infinite precision
Triple Bond
-When two atoms share three electron pairs -Generally shorter than single and double bonds
Double Bond
-When two atoms share two electron pairs -Generally shorter than single bonds
s Orbitals
-l = 0 -Lowest energy orbital -Spherically symmetrical -3D plot of ψ²
p Orbitals
-l=1 -3 (ml = -1,0,1) contained in each principal level n=2 or greater; each is different indirection, but mutually perpendicular (orthogonal) -Not spherically symmetrical; 2 lobes of electron density on either side of the nucleus -1 node at the nucleus
d Orbitals
-l=2 -5 (ml = -2,-1,0,1,2) contained in each principal level n=3 or greater -Clover leave shape with 4 lobes of electron density and 2 perpendicular nodal planes
f Orbitals
-l=3 -7 (ml = -3,-2,-1,0,1,2,3) contained in each principal level n=4 or greater -More lobes and nodes than d orbitals
The probability of finding an electron at a node is _____.
0
How many moles (of molecules or formula units) are in each sample? 37.75 g CF₂Cl₂ 20.4 kg Fe(NO₃)₂ 0.2536 g C₈H₁₈ 147 kg CaO
0.3122 mol 113 mol 2.22 x 10⁻³ 2620 mol
Use the periodic table to determine the number of 3s electrons in Na.
1
Use the periodic table to determine the number of 4d electrons in Y.
1
mon =
1
How many sublevels are in the 1s level?
1 l = 0
What does a 1s orbital tell us?
1 = value of n s specifies that l=0 ml = 0
Determine the number of each type of atom in Ba(OH)₂
1 barium atom, 2 oxygen atoms and 2 hydrogen atoms
Determine the number of each type of atom in NaNO₃
1 sodium atom, 1 nitrogen atom and 3 oxygen atoms
What three properties explain splitting among orbitals?
1. Coulomb's law 2. Shielding 3. Penetration
What are the 3 manifestations of the electron's wave nature?
1. The de Brogile wavelength 2. The uncertainty principle 3. Interdeterminacy
What are the 3 orbitals?
1. n = principal quantum number 2. l = angular momentum quantum number 3. ml = magnetic quantum number *all have integer values
deca =
10
Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in which n = 3 to an orbital in which n =6.
1090 nm
1 nm = ___ m
10⁻⁹
The s sublevel has _____ orbitals, and can hold _____ electrons.
1;2
What orbital(s) does an element with 2 electrons have?
1s²
What orbital(s) does an element with 4 electrons have?
1s², 2s²
What orbital(s) does an element with 12 electrons have?
1s², 2s², 2p⁶, 3s²
What orbital(s) does an element with 20 electrons have?
1s², 2s², 2p⁶, 3s², 3p⁶, 4s²
What orbital(s) does an element with 38 electrons have?
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s²
What orbital(s) does an element with 56 electrons have?
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s²
What orbital(s) does an element with 72 electrons have?
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², 4f¹⁴, 5d²
What is the electron configuration of N³⁻?
1s²2s²2p⁶
How many electrons can each orbital hold?
2
di =
2
How many sublevels are in the 2s level?
2 l = 0,1
Determine the number of each type of atom in (NH₄)₂S
2 nitrogen atoms, 8 hydrogen atoms and 1 sulfur atom
Calculate the wavelength of an electron traveling with a speed of 2.65 x 10⁶ m/s.
2.74 x 10⁻¹⁰ 1. Get from v → λ 2. λ = h /mv λ = (6.626 x 10⁻³⁴)/(9.11 x 10⁻³¹)(2.65 x 10⁶)
Silver chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride required to plate 205 mg of pure silver.
272 mg
The number of orbitals in any sublevel is equal to _____.
2l + 1 s → 1 orbital p → 3 orbitals d → 5 orbitals
How can you calculate how many total electrons are in a shell?
2n²
At what period do you start using noble gas notation?
3
How many valence electrons are in Al?
3
tri =
3
How many sublevels are in the 3s level?
3 l = 0,1,2
The velocity of an electron in the ground-state energy level of hydrogen is 2.2 x 10⁶ m/s. If the electron's mass is 9.1 x 10⁻³¹ kg, what is the de Broglie wavelength of this electron?
3.3×10⁻¹⁰ m
Calculate the number of grams of sodium in 8.3 g of each of the following sodium-containing food additives. Na₃PO₄ (sodium phosphate) NaC₇H₅O₂ (sodium benzoate)
3.5 g 1.3 g
The p sublevel has _____ orbitals, and can hold _____ electrons.
3;6
Which are silicon's valence electrons? 1s²2s²2p²3s²3p²
3s²3p²
Use the periodic table to determine the number of 6p electrons in Po.
4
tetra =
4
Calculate the mass (in grams) of each sample. 5.2 x 10²⁵ O₃ molecules 6.00 x 10¹⁹ CCl₂F₂ molecules 9 water molecules
4100 g 1.20 x 10⁻² g 2.693 x 10²² g
What is the molar mass of CO₂?
44.01 g/mol
Write the orbital diagram for Zr²⁺. Is it diamagnetic or paramagnetic?
4d ↑ ↑ 5s 4p ↑↓ ↑↓ ↑↓ 3d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 4s ↑↓ 3p ↑↓ ↑↓ ↑↓ 3s ↑↓ 2p ↑↓ ↑↓ ↑↓ 2s ↑↓ 1s ↑↓ Paramagnetic
Write the orbital diagram for Mo³⁺. Is it diamagnetic or paramagnetic?
4d ↑ ↑ ↑ 5s 4p ↑↓ ↑↓ ↑↓ 3d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 4s ↑↓ 3p ↑↓ ↑↓ ↑↓ 3s ↑↓ 2p ↑↓ ↑↓ ↑↓ 2s ↑↓ 1s ↑↓ Paramagnetic
Write the orbital diagram for Cd²⁺. Is it diamagnetic or paramagnetic?
4d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 5s 4p ↑↓ ↑↓ ↑↓ 3d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 4s ↑↓ 3p ↑↓ ↑↓ ↑↓ 3s ↑↓ 2p ↑↓ ↑↓ ↑↓ 2s ↑↓ 1s ↑↓ Diamagnetic
Which electron is, on average, further from the nucleus: an electron in a 3p orbital or an electron in a 4p orbital?
4p
Use the periodic table to determine the number of 3d electrons in Cr.
5
penta =
5
The d sublevel has _____ orbitals, and can hold _____ electrons.
5;10
Write the orbital diagram for Au⁺. Is it diamagnetic or paramagnetic?
5d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 4f ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 5p ↑↓ ↑↓ ↑↓ 4d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 5s ↑↓ 4p ↑↓ ↑↓ ↑↓ 3d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 4s ↑↓ 3p ↑↓ ↑↓ ↑↓ 3s ↑↓ 2p ↑↓ ↑↓ ↑↓ 2s ↑↓ 1s ↑↓ Diamagnetic
hexa =
6
An element in the lettered group 7A has _____ electrons.
7
hepta =
7
Calculate the mass of each sample. 19.5 mol HCl 1.20 x 10⁻³ mol H₂O 75.6 mmol SO₂ 1.28 mol xenon dichloride
711 g 2.16 x 10⁻² g 4.84 g 259 g
The f sublevel has _____ orbitals, and can hold _____ electrons.
7;14
octa =
8
Calculate the mass percent composition of nitrogen in each of the following nitrogen compounds. NH₃ Si₃N₄
82.25% 39.94%
Which column contains the noble gases?
8A/18
nona =
9
What is the resting mass of an electron?
9.1094 x 10⁻³¹
What is the mass of an electron?
9.11 x 10⁻³¹ kg
Determine the number of moles of oxygen atoms in each of the following. 4.77 mol H₂O₂ 2.07 mol N₂O 2.33 x 10⁻² mol H₂CO₃ 23.4 mol CO₂
9.54 mol 2.07 mol 6.99 x 10⁻² mol 46.8 mol
The fastest baseball pitch ever recorded was approximately 46.7 m/s. If a baseball has a mass of 0.145 kg, what is its de Broglie wavelength?
9.78×10⁻³⁵ m
Atomic Mass = _____ + _____
A = protons + neutrons
Non-Bonding (Lone) Pair
A pair of electrons associated with only one atom
Node
A point where the wave function, probability density, and radical distribution function all go through 0
Magnetic Field
A region of space where a magnetic particle experiences a force
Electric Field
A region of space where an electrically charged particle experiences a force
Bonding Pair
A shared pair of electrons
Orbital
A way of describing an electron's position using a probability distribution map by showing where electrons are likely to be found Symbol: ψ²
What does "quantum" mean?
Absolutely small
Use Lewis theory to determine the formula for the compound that forms between the two elements listed. Al and N Cs and S
AlN Cs₂S
Consider the following set of successive ionization energies: IE1=578kJ/mol IE2=1,820kJ/mol IE3=2,750kJ/mol IE4=11,600kJ/mol To which third period element do these ionization values belong?
Aluminum
We can characterize a wave by its _____ and _____.
Amplitude; wavelength
Diamagnetic
An atom or ion that contains all paired electrons, so it is not attracted to an external magnetic field
Paramagnetic
An atom or ion that contains unpaired electrons, so it is attracted to an external magnetic field
What are the possible values of n?
Any integer 1 or greater
Choose the element with the highest first ionization energy from each of the following pairs. Ar or Kr Si or Cl S or Te
Ar Cl S
Choose the larger atom from each of the following pairs. As or N Br or Ga Sn or Ge S or Ge
As Ga Sn Ge
As the wavelength of a photon increases, what happens to the photon's energy?
As the wavelength of a photon increases, its energy decreases. According to Planck's equation, the energy of a photon is proportional to the light frequency, E=hν. The light frequency, ν, is inversely proportional to wavelength, c=λν, where c is the speed of light. That means that increasing the wavelength decreases the light's frequency.
Space-Filling Molecular Model
Atoms fill the space between each other to more closely represent the estimate of the molecule if it were scaled to visible size
A metal (M) forms an oxide with the formula MO. If the oxide contains 63.97 % O by mass, what is the identity of the metal?
Be
Express your answer as a chemical symbol. [Ar]4s²3d¹⁰4p⁵
Br
Give each ionic compound an appropriate name. CaS FeS PbF₂ SrI₂
Calcium sulfide Iron(III) sulfide Lead(II) fluoride Strontium iodide
Binary Compounds Forming More than 1 Ion
Cation name + roman numeral indicating charge + anion name + -ide i.e. Fe²⁺ = iron(II)
Predict the charge of the ion formed by each of the following elements. Express your answer as an ion. Ca
Ca²⁺
Why are orbital shapes important?
Chemical bonds depend on the sharing of the electrons that occupy orbitals
Arrange the following elements in order of decreasing first ionization energy: Bi, Cl, Sb, and Br
Cl Br Sb Bi
Arrange the following elements in order of decreasing first ionization energy: Bi, Cl, Sb, and Br.
Cl, Br, Sb, Bi
Predict the charge of the ion formed by each of the following elements. Express your answer as an ion. Cl
Cl⁻
The wavelength of light determines its _____.
Color
p Block Elements
Column 13-18 of the periodic table minus helium (He)
The number of _____ in a block corresponds to the maximum number of electrons that can occupy the particular sublevel of that block.
Columns i.e. s block has 2 columns, p block has 6, d block has 10, and f block has 14
d Block Elements
Columns 3-12 of the periodic table
What is the electron configuration and orbital diagram for Be?
Configuration: 1s²2s² Diagram: ↑↓ ↑↓ 1s 2s
What is the electron configuration and orbital diagram for C?
Configuration: 1s²2s²2p² Diagram: ↑↓ ↑↓ ↑ ↑ 1s 2s 2p
What is the electron configuration and orbital diagram for O?
Configuration: 1s²2s²2p⁴ ↑↓ ↑↓ ↑↓ ↑ ↑ 1s 2s 2p
What is the electron configuration and orbital diagram for Li?
Configuration: 1s²2s¹ Diagram: ↑↓ ↑ 1s 2s
What is the electron configuration for helium (He)? What is the orbital diagram?
Configuration: He 1s² Diagram: ↑↓ 1s
What is the electron configuration and orbital diagram for Ne?
Configuration: [He] 2s²2p⁶ Diagram: ↑↓ ↑↓ ↑↓↑↓↑↓ 1s 2s 2p
What is the electron configuration and orbital diagram for Si?
Configuration: [Ne] 3s²3p² Diagram: ↑↓ ↑↓ ↑↓↑↓↑↓ ↑↓ ↑↑ 1s 2s 2p 3s 3p
White light spectrum is (interrupted/continuous), while emission spectrum is (interrupted/continuous).
Continuous; interrupted
(Core/Outer) electrons efficiently shield electrons in the outermost principal energy level from nuclear charge, but (core/outer) electrons do not efficiently shield one another from nuclear charge.
Core; outer
Molecular Compounds
Covalently bonded atoms that form molecules
Arrange the following elements in order of decreasing atomic radius: Cs, Sn, Cl, Tl, and As.
Cs, Ti, Sn, As, Cl As you move down a column (or family) in the periodic table, atomic radius increases. As you move to the right across a period (or row) in the periodic table, atomic radius decreases. Thus, Cs has the largest atomic radius of the elements given, and Cl has the smallest atomic radius of the elements given.
Write a formula for the ionic compound that forms between the pair of elements. Caesium and Chlorine Potassium and Oxygen Strontium and Iodine
CsCl K₂O SrI₂
Calculate the empirical formula for each of the following natural flavors based on their elemental mass percent composition. Methyl butyrate: 58.80%C, 9.87%H, and 31.33%O. Vanillin: 63.15%C, 5.30%H, and 31.55%O. Malonic acid: 34.63% C, 3.87% H, and 61.50% O
C₅H₁₀O₂ C₈H₈O₃ C₃H₄O₄
Combustion analysis of a hydrocarbon produced 33.01 g CO₂ and 4.83 g H₂O. Calculate the empirical formula of the hydrocarbon.
C₇H₅ 1. Find moles 33.01g x (1 mol/12.01+16+16) x (1 mol/1 mol) x (12.01 g/1 mol) = 9.008g 9.008 g x (1 mol/12.01 g) = 0.75 mol 4.83g x (1 mol/1.008+1.008+16) x (1 mol/1 mol) x (1.008 g/1 mol) = 0.5405 g 0.5405 g x (1 mol/1.008 g) = 0.536 mol 2. Divide by smallest number 0.75/0.536 = 1.399 0.536/0.536 = 1 3. Find whole number 1.399 x 5 = 6.99 1 x 5 = 5
The molar mass and empirical formula of several compounds are listed below. Find the molecular formula of each compound. C₄H₉, 114.19 g/mol CCl, 284.78 g/mol C₃H₂N, 312.43 g/mol
C₈H₁₈ C₆Cl₆ C₁₈H₁₂N₆
Ionization generally (decreases/increases) as we move down the periodic table, and (decreases/increases) as we move right.
Decreases → electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and therefore held less tightly Increases → electrons in the outermost principal level generally experience a greater effective nuclear charge
Sublevel Electron Splitting
Determines the order of orbital filling within a level
Ionic compounds (do/do not) conduct electricity as solids, but (do/do not) conduct electricity when dissolved in water.
Do not; do
The density of elements tends to increases as you move (up/down) a column in the periodic table. Why?
Down Because the mass of each successive atom increases even more than its volume does due to additional protons and neutrons
As we move (up/down) a column in the periodic table, the atomic radius increases. As we move right across a period, the atomic radius (decreases/increases).
Down; decreases
How much energy is contained in 1 mol of γ-ray photons with a wavelength of 2.72×10−5 nm? Express the energy numerically in kilojoules per mole.
E = 4.40 x 10⁹ kJ/mol The high energy of x-ray photons and gamma photons are able to ionize atoms and molecules. This property can cause DNA damage directly or indirectly, which is why they are carcinogenic.
Calculate the energy of a photon of electromagnetic radiation at each of the following frequencies. 835.3 MHz (common frequency used for cell phone communication). Express your answer in joules using four significant figures.
E = 5.535 x 10⁻²⁵ J It was Albert Einstein who first proposed that light energy came in quantifiable packets. The energy of a photon depends on its frequency, with higher frequencies corresponding to higher energy photons. Since E = hc/λ, where c is the speed of light in m/s and λ is the wavelength of light, it can also be said that shorter wavelengths correspond to higher energy photons.
Calculate the energy of a photon of electromagnetic radiation at each of the following frequencies. 101.8 MHz (typical frequency for FM radio broadcasting). Express your answer in joules using four significant figures.
E = 6.745 x 10⁻²⁶ J 1. To convert a value from MHz to J, start by converting the value to Hz using the conversion factor 10⁶ Hz/1 MHz. 2. Since 1 Hz = 1 s⁻¹, you can now substitute this value into the equation E = hν, where h = 6.626 × 10⁻³⁴ J⋅s and ν is frequency.
Calculate the energy of a photon of electromagnetic radiation at each of the following frequencies. 1065 kHz (typical frequency for AM radio broadcasting). Express your answer in joules using four significant figures.
E = 7.057 x 10⁻²⁸ J 1. To convert a value from kHz to J, start by converting the value to Hz using the conversion factor 10³ Hz/1 kHz. 2. Since 1 Hz = 1 s⁻¹, you can now substitute this value into the equation E = hν, where h = 6.626 × 10⁻³⁴ J⋅s and ν is frequency.
How much energy is contained in 1 mol of X-ray photons with a wavelength of 0.135 nm? Express the energy numerically in kilojoules per mole.
E = 8.87 x 10⁵ kJ/mol 1. To find the amount of energy per photon, start by converting the wavelength of the photon from nm to m using the conversion factor 1m/10⁹ nm. 2. Then, substitute the values into the equation E = hc/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength of the photon.
What do the symbols stand for? E = hv
E = amount of energy in the light packet v = frequency h = Planck's constant
What do these symbols represent? E = hc/λ
E = energy of a photon h = Planck's constant c = speed of light λ = wavelength
Formula for the Energy of a Photon
E = hc/λ
What equation equates to the E in E = KE + Φ?
E = hv
What does each symbol stand for? E = KE + Φ
E = photon energy KE = kinetic energy Φ = work function
What does each symbol represent? E = (1/4πε₀)(q₁q₂/r)
E = potential energy ε₀ = 8.85 x 10⁻¹² C²/Jm q₁ and q₂ = charges r = separation
Family/Group of Elements
Each column within the main-group regions of the periodic table
Light is _____.
Electromagnetic radiation
What are core electrons?
Electrons that reside in complete principal energy levels and in complete d and f levels
Main-Group Elements
Elements whose properties tend to be largely predictable based on their position in the periodic table
Transition Elements (Metals) and Inner Transition Elements
Elements whose properties tend to be less predictable based on their position in the periodic table
What does a negative sign tell us?
Energy emission *Energy emitted is carried away by a photon
What are you finding in Planck's equation E = hv?
Energy of a photon absorbed or emitted
We can specify an electron's (energy/location), but not it's (energy/location) at a given instant
Energy; location
The number of electrons in a neutral atom is (less than/equal to/greater than) the atomic number
Equal to
Quantum-Mechanical Model
Explains the strange behavior of electrons and how they exist within atoms
What does each symbol mean? F = kq₁q₂/r²
F = force (mass x acceleration) k = proportionality constant q₁ = first charge q₂ = second charge r² = distance between charges
True or false: Increasing the intensity of low frequency light will allow it to dislodge electrons.
False
True or false: we can calculate deterministic electron trajectories.
False
The arrangements of elements on the periodic table reflects how electrons _____.
Fill quantum-mechanical orbitals
What is the basic unit of an ionic compound?
Formula unit
What would you expect to happen to the frequency of a light wave if its wavelength were increased by a factor of 10?
Frequency and wavelength are inversely proportional. If we increase the wavelength by a factor of 10, then the frequency will decrease to 1/10 of its initial value.
Predict the charge of the ion formed by each of the following elements. Express your answer as an ion. F
F⁻
Which form of electromagnetic radiation has the shortest wavelength?
Gamma (γ) rays
Arrange these waves from the left side (high frequency side) of the electromagnetic spectrum: FM Gamma Ray Microwaves Other radio waves X-Rays AM Infrared Visible Light UV Rays
Gamma Rays X-Rays UV Ways Visible Light Infrared Microwave FM AM Other radio waves
Empirical Chemical Formula
Gives the relative number of atoms of each element in a compound i.e. hydrogen peroxide → HO
Anions have a much (smaller/greater) radii than their neutral counterparts.
Greater
Short wavelengths inherently has (greater/less) energy than long wavelengths
Greater
The wavelength of orange light is about 590-635 nm and the wavelength of green light is about 520-560 nm. Which color of light is more energetic, orange or green?
Green light is more energetic than orange light. This is because green light has a shorter wavelength, and thus a higher frequency and a higher energy, than orange light.
What does each symbol represent? Hψ = Eψ
H = Hamiltonian operator (total kinetic energy of the electron within the atom) ψ = wave function E = actual energy of the electron (binding energy)
(Low/High) frequency light ejects electrons according to the photoelectric effect.
High
The row number of a main-group element is equal to the _____ of that element.
Highest principal quantum number
Schrodinger Equation of the Atom of Interest
Hψ = Eψ
Express your answer as a chemical symbol. [Kr]5s²4d¹⁰5p¹
In
According the Coulomb's Law, the magnitude of the interaction between charged particles (decreases/increases) as the charges of the particles increases.
Increases
According to Coulomb's law, the attraction between a nucleus and an electron (decreases/increases) with increasing magnitude of nuclear charge.
Increases
According to the photoelectric theory, electric current (decreases/remains constant/increases) with light amplitude
Increases
According to the photoelectric theory, the kinetic energy of photoelectrons (decreases/increases) with light frequency
Increases
As we move right across the periodic table, the effective nuclear charge (Zeff) experienced by the electrons in the outermost principal energy level (decreases/increases), resulting in a stronger attraction between the outermost electrons and the nucleus, and smaller atomic radii.
Increases
Contrary to the predictions, photoelectric effect experiments showed that (decreasing/increasing) the light frequency increased the kinetic energy of the photoelectrons, and increasing the light amplitude increased the current.
Increasing
The amplitude of the electric and magnetic field waves in light determines the light's _____.
Intensity/brightness
Classify each of the following compounds as ionic or molecular. HCN PtO₂ CCl₄ Ni₃ Cr₂O₃
Ionic: PtO₂, Cr₂O₃ Molecular: HCN, CCl₄, Ni₃
The electron interference pattern (is/is not) caused by single electrons interfering with themselves.
Is
The electron interference pattern (is/is not) caused by pairs of electrons interfering with each other.
Is not
What equation equates to the KE in E = KE + Φ?
KE = hv - Φ OR KE = 1/2mv²
How do you determine the kinetic energy of an emitted electron?
KE = hv - ∅
What does each symbols represent? KE = 1/2mv²
KE = kinetic energy m = electron mass v = frequency/velocity
Metallic character increases as you go (right/left) across a period and as you go (down/up) a group of the periodic table.
Left; down
According to the Uncertainty Principle, the more accurately you know the position of an electron (the smaller ∆x), the (less/more) accurately you know its velocity (the bigger ∆v), and vice versa.
Less
Except for helium, the number of valence electrons for any main-group element is equal to its _____.
Lettered group number
Type a formula for the compound that forms between lithium and each polyatomic ion: Carbonate (CO₃²⁻) Phosphate (PO₄³⁻) Hydrogen Phosphate (HPO₄²⁻) Acetate (C₂H₃O₂⁻)
Li₂CO₃ Li₃PO₄ Li₂HPO₄ LiC₂H₃O₂
Transitions between stationary states that are closer together produce a (shorter/longer) wavelength than transitions between stationary states that are farther apart.
Longer
When a quantum level is completely full, the overall potential energy of the electrons that occupy that level is particularly (low/stable/high).
Low
In non-degenerate atoms (multi-electron), the lower the value of l within a principle level, the (lower/higher) the energy of the corresponding orbital.
Lower For a given value of n: E (s orbital) < E (p orbital) < E (d orbital) < E (f orbital)
Electrons generally occupy the _____ level available.
Lowest
How does adding and removing electrons from the electron configuration of main group element differ from transitional?
Main group: remove in reverse order of filling Transitional: remove electrons in the highest n-value orbitals first, even if this does not correspond to the reverse order filling
What is the general conceptual plan for finding the mass of an element present in a given mass of a compound?
Mass compound → moles compound → moles element → mass element
Electrons occupy orbitals so as to (minimize/stabilize/maximize) the energy of the atom.
Minimize
What is the mass percentage of Cl in CCL₂F₂?
Molar mass Cl = 12.01 + 2(35.45) + 2(19) = 120.91 Mass % = 2(35.45)/120.91 x 100% = 58.64%
The chemical equation gives us a relationship between the amounts in (grams/moles) of substances.
Moles
The faster a wave is traveling, the _____ crests it will have.
More
A laser pulse with wavelength 510 nm contains 4.85 mJ of energy. How many photons are in the laser pulse?
N = 1.24×10¹⁶ E = hc/l # of photons = total energy/ energy per photon
A salt crystal has a mass of 0.15 mg. How many NaCl formula units does it contain?
N = 1.5 x 10¹⁸
Determine the empirical formula for the compound represented by the molecular formula. N₂O₄
NO₂
According to Coulomb's Law, the potential energy associated with the interaction of unlike charges is (negative/positive) and becomes (more/less) negative as the particles get closer together.
Negative; more
Why don't low-frequency lights eject electrons?
No single photon has the minimum energy necessary to dislodge the electron
What are the least reactive elements? Why?
Noble gases; they have 8 valence electrons and full outer quantum levels making them stable
What forces an electron into a single state?
Observation
Elemental Organization by John Newlands (1837-1898)
Octaves: properties of every 8th element was similar, like 8th notes in music
The principal quantum number of the d orbitals that fill across each row in the transition series is (one less than/equal to/one more than) the row number.
One less than i.e. row 4 has 3d; row 5 has 4d
How are Bohr's orbits different from planetary orbits?
Orbits exist only at specific, fixed distances from the nucleus
Elemental Organization by Henry Moseley (1887-1915)
Organized by atomic number to solve some issues with Mendeleev's method
Where are valence electrons in main-group elements?
Outermost principal energy level (shell)
Where are valence electrons in transition-group elements?
Outermost principal energy level (shell) and the outermost d level (shell)
A packet of light is called a _____.
Photon or quantum of light
The _____ of an electron is related to its particle nature.
Position Particles have well-defined positions
According to Coulomb's Law, the potential energy is (negative/positive) for the interaction of charges with the same sign.
Positive
Naming Molecular Compounds
Prefix* + name of first element + prefix + name of second element + -ide *if its one for the first element, mono- is omitted i.e. NO₂ = nitrogen dioxide N₂O = dinitrogen monoxide
Orbitals with the same n value are said to be in the same _____.
Principal level
What is used in place of trajectories in quantum mechanics?
Probability distribution maps
Elemental families have similar _____.
Properties
A 45.6 mg sample of phosphorus reacts with selenium to form 133 mg of the compound. What is the empirical formula of the phosphorus selenide?
P₄Se₃ 133 mg - 45.6 mg = 87.4 mg Se (45.6 mg P)/(30.97 g/mol) = 1.47 mmol P (87.4 mg Se)/(78.96 g/mol) = 1.12 mmol Se 1.47/1.12 = 1.313 1.12/1.12 = 1 3(1.313) ≈ 4 3(1) = 3
Express your answer as a chemical symbol. [Kr]5s¹
Rb
Arrange the following elements in order of decreasing metallic character: Rb, N, Si, P, Ga, and Ge.
Rb, Ga, Ge, Si, P, N The metallic character of an element correlates with its macroscopic properties, such as heat and electric conductivity. Metallic character increases as you go left across a period and as you go down a group of the periodic table.
The color we see is the color that is (absorbed/reflected)
Reflected
According to the photoelectric theory, electric current (decreases/remains constant/increases) as light frequency increases
Remains constant
According to the photoelectric theory, the kinetic energy of photoelectrons (decreases/remains constant/increases) as light amplitude increases
Remains constant
Which electrons experience the greatest effective nuclear charge? Express your answer as a chemical formula. Mg, Al, S
S
Choose the element with the more negative (more exothermic) electron affinity from each of the following pairs. Mg or S H or Na C or As
S H C
Arrange the following atoms according to decreasing effective nuclear charge experienced by their valence electrons: S, Na, Al, and Si.
S, Si, Al, Na
Arrange the following isoelectronic series in order of increasing atomic radius: Cl⁻, Sc³⁺, S²⁻, Ca²⁺, and K⁺.
Sc³⁺ Ca²⁺ K⁺ Cl⁻ S²⁻
Transitions between orbitals that are further apart in energy produce a light that is higher in energy, therefore (shorter/longer) wavelength.
Shorter
Cations have a much (smaller/greater) radii than their neutral counterparts.
Smaller
The smaller the amplitude, the _____ the intensity/brightness.
Smaller
Wave-Particle Duality of Light
Sometimes light appears to behave like a wave, at other times like a particle
Pick the larger species from each of the following pairs. Sr or Sr²⁺ P or P³⁻ Rh or Rh²⁺ S²⁻ or Ca²⁺
Sr P³⁻ Rh S²⁻
A we move down a column in the periodic table, the number of electrons in the outermost principal energy level (highest n value) (decrease/stays the same/increases).
Stays the same
As we move right across the periodic table, the effective nuclear charge (Zeff) experienced by the electrons in the outermost principal energy level increases, resulting in a (stronger/weaker) attraction between the outermost electrons and the nucleus, and smaller atomic radii.
Stronger
Which provides more information: empirical or structural formulas?
Structural
_____ determines properties.
Structure
Orbitals with the same n and l value are said to be in the same _____.
Sublevel
Noble Gas Notation with Main Elements
Take the noble gas preceding the element, then add the other electrons (a.k.a valence electrons) not included by the noble gas [Noble Gas] other electrons i.e. Si → [Ne] 3s²3p² Ca → [Ar] 4s² (also written as Ca²⁺)
f Block Elements
The Lanthanides (elements 58-71) and Actinides (elements 90-103)
Effective Nuclear Charge
The average (net charge) experienced by an electron
Why don't we see the wavelength characteristics of electrons?
The de Broglie wavelength and particle mass are inversely proportional. The inverse relationship is why we don't notice any wavelike behavior for the macroscopic objects we encounter in everyday life
Nonbinding Atomic Radius (van der Waals Radius)
The distance between nonbinding atoms that are in direct contact
Where do you find the inner electron configurations?
The final column of the periodic table *The final element on the row above the element you are configuring is its inner electron configurations
s Block Elements
The first 2 rows of the periodic table plus helium (He)
Ground State
The lowest energy state of an electron
What does deterministic mean?
The present determines the future
Orbital Phase
The sign (+ or -) of the amplitude of a wave
What causes sublevel splitting?
The spatial distribution of electrons within a sublevel
Atomic Spectroscopy
The study of the electromagnetic radiation absorbed and emitted by atoms -When an atom absorbs energy, it often remits that energy as light -Atoms of each element emit light of a characteristic color -Contains various wavelengths
Why do chemical bonds form?
They lower the potential energy of the charged particles that compose atoms
What happens to the atomic radii of transition elements as you move across the rows? Why?
They stay roughly constant; The number of electrons on the outermost principal level is nearly constant
Planck found that the electromagnetic radiation emitted by blackbodies could not be explained by classical physics, which postulated that matter could absorb or emit any quantity of electromagnetic radiation. Planck observed that matter actually absorbed or emitted energy only in whole-number multiples of the value hν, where h is Planck's constant, 6.626 x 10⁻³⁴ J⋅s is the frequency of the light absorbed or emitted. Why was this so shocking?
This was a shocking discovery, because it challenged the idea that energy was continuous, and could be transferred in any amount. The reality, which Planck discovered, is that energy is not continuous but quantized—meaning that it can only be transferred in individual "packets" (or particles) of the size hv. Each of these energy packets is known as a quantum (plural: quanta).
Express your answer as a chemical symbol. [Ar]4s²3d²
Ti
Radial Distribution Function
Total radial probability (at given r) = (probability/unit volume) x volume of shell at r The total probability of finding the electron within a thin spherical shell at a distance r from the nucleus
What type of elements generally make ionic compounds that produce more than one type of ions?
Transition metals
Elemental Organization by Johann Dobereiner (1780-1849)
Triads: groups of 3 elements with similar properties
True or false: Increasing the frequency of low frequency light increases the energy of each photon and allows it to dislodge electrons
True
True or false: Light shares many characteristics with electrons. (i.e. wave-particle duality)
True
True or false: the number of sublevels is equal to n.
True
Quantum particles like electrons can be in _____ states at the same time.
Two different
The principal quantum number of the f orbitals that fill across each row in the transition series is (two less than/equal to/two more than) the row number.
Two less than i.e. row 6 has 4f; row 7 has 5f
Atomic radius is largely determined by the _____.
Valence electrons
The chemical properties of an element depends on it _____.
Valence electrons
The _____ of an electron is related to its wave nature.
Velocity Waves do not have well-defined positions
Particles move in a trajectory that is determined by the particle's _____, _____, and _____
Velocity, position, the forces acting on it
Amplitude
Vertical height of a crest or depth of a trough
In a covalently bonded molecular compound, the interactions between molecules −intermolecular forces− are generally much (weaker/stronger) than the bonding interactions within a molecule −intramolecular forces−.
Weaker
Diffraction
When a wave encounters an obstacle or a slit that is comparable in size to its wavelengths, it bends around the light
Hund's Rule
When filling degenerate orbitals, electrons fill them singly first, with parallel spins
Destructive Interference
When two waves of are out of phase, resulting in the crests and troughs cancelling each other out
Constructive Interference
When two waves of the same amplitude interact and are in phase, resulting in a wave that is twice the amplitude
What is the electron configuration of Cl?
[Ne] 3s²3p⁵
What is the electron configuration for Cl⁻? P³⁻? K⁺? Mo³⁺?
[Ne]3s²3p⁶ [Ne]3s²3p⁶ [Ne]3s²3p⁶ [Kr]4d³
Which of the following combinations of n and l represent impossible orbits? a. 1p b. 2p c. 3p d. 5s
a. 1p
Suppose that, in an alternate universe, the possible values of ml were the integer values including 0 ranging from −l−1 to l+1 (instead of simply −l to +l). How many orbitals would exist in each of the following sublevels? a. s sublevel b. p sublevel c. d sublevel
a. 3 b. 5 c. 7
Suppose that in an alternate universe, the possible values of l were the integer values from 0 to n (instead of 0 to n−1). Assuming no other differences from this universe, how many orbitals would exist in each of the following levels? a. n=1 b. n=2 c. n=6
a. 4 orbitals b. 9 orbitals c. 49 orbitals
Determine whether each of the following transitions in the hydrogen atom corresponds to absorption or emission of energy. a. n = 2 → n = 4 b. n = 3 → n = 1 c. n = 4 → n = 3
a. Absorption b. Emission c. Emission
When we shine light with a frequency of 6.20×10¹⁴ Hz on a mystery metal, we observe the ejected electrons have a kinetic energy of 3.28×10⁻²⁰ J Calcium, 4.60×10⁻¹⁹ Tin, 7.08×10⁻¹⁹ Sodium, 3.78×10⁻¹⁹ Hafnium, 6.25×10⁻¹⁹ Samarium, 4.33×10⁻¹⁹ Based on this information, what is the most likely identity of our mystery metal? a. Sodium, Na B. Calcium, Ca C. Tin, Sn D. Samarium, Sm
a. Sodium, Na Since we know the frequency of the incident light and the kinetic energy of the photoelectrons, we can find the work function of our mystery metal using the following equation: E =hν=KE +Φ We can rearrange the equation so that we are solving for Φ: Φ=hν−KE
According to Coulomb's law, rank the interactions between charged particles from lowest potential energy to highest potential energy. a. a 1+ charge and a 1- charge separated by 100 pm b. a 2+ charge and a 1- charge separated by 100 pm c. a 1+ charge and a 1+ charge separated by 100 pm d. a 1+ charge and a 1- charge separated by 200 pm
b, a, d, c
Which set of quantum numbers cannot occur together to specify an orbital? a. n=3,l=1,mι=−1 b. n=4,l=2,mι=0 c. n=3,l=2,mι=3 d. n=2,l=1,mι=−1
c. n=3,l=2,mι=3
Which element block makes up the transition-group elements?
d and f
What replaced the Bohr model?
de Brogile Model
What does each symbol represent? hv = ∅
h = Planck's constant v = frequency ∅ = binding energy or emitted electron
Sublevel is specified by (n/l/ml).
l
What quantum number determines shape of the orbital?
l
While hydrogen atoms' orbital energy depends only on n, multi-electron atoms depend on the value of (n/l/ml).
l
What are the possible values of l when n = 1?
l = 0
If n =1, what are the following values? l = ml = Orbital = number of electrons in the orbital number of electrons in the shell
l = 0 ml = 0 1s orbital 2 electrons 2 electrons
If n =2, what are the following values? l = ml = Orbital = number of electrons in the orbital number of electrons in the shell
l = 0, 1 ml = -1, 0, 1 1s and 3p orbitals 2 electrons in s, 6 in p 8 electrons
If n =3, what are the following values? l = ml = Orbital = number of electrons in the orbital number of electrons in the shell
l = 0, 1, 2 ml = -2, -1, 0, 1, 2 1s, 3p, 5d orbitals 2 electrons in s, 6 in p, 10 in d 18 electrons
If n =4, what are the following values? l = ml = Orbital = number of electrons in the orbital number of electrons in the shell
l = 0, 1, 2, 3 ml = -3, -2, -1, 0, 1, 2, 3 1s, 3p, 5d, 7f orbitals 2 electrons in s, 6 in p, 10 in d, 14 in f 32 electrons
What are the possible values of l when n = 2?
l = 0,1
What are the possible values of l when n = 3?
l = 0,1,2
What are the possible values of l when n = 4?
l = 0,1,2,3
What is the SI unit for wavelength?
meters (m)
Which quantum number specifies orbital orientation?
ml
What are the possible values of mι when l = 1?
mι = -1,0,1
What are the possible values of mι when l = 2?
mι = -2,-1,0,1,2
What are the possible values of mι when l = 3?
mι = -3,-2,-1,0,1,2,3
What are the possible values of mι when l = 0?
mι = 0
Primary level is specified by (n/l/ml).
n
Which quantum number determines the size and energy of the orbital?
n
An electron in the n=7 level of the hydrogen atom relaxes to a lower energy level, emitting light of 397 nm. What is the value of n for the level to which the electron relaxed?
n = 2
What are the possible values of l?
n-1, including 0
What is the unit of wavelength?
nm
Which of the following outer electron configurations would you expect to belong to a reactive metal? Check all that apply. ns²np⁵ ns²np² ns² ns²np⁶
ns²
Which of the following outer electron configurations would you expect to belong to a noble gas? Check all that apply. ns²np⁵ ns²np² ns² ns²np⁶
ns² ns²np⁶
Which of the following outer electron configurations would you expect to belong to a nonreactive metal? Check all that apply. ns²np⁵ ns²np² ns² ns²np⁶
ns²np⁵
Which of the following outer electron configurations would you expect to belong to a metalloid? Check all that apply. ns²np⁵ ns²np² ns² ns²np⁶
ns²np⁵ ns²np²
The number of orbitals in a level is equal to _____.
n² n=1 → 1 orbital n=2 → 4 orbitals n=3 → 9 orbitals
Which element blocks make up the main-group elements?
s and p
What are the letter designations when l=1, l=2, l=3, and l=4?
s, p, d, f
Calculate the frequency of the light emitted when an electron in a hydrogen atom makes a transition from n=4→n=3.
v = 1.60 x 10¹⁴ s⁻¹ 1. To calculate the frequency, you should have started by using the equation ΔE=−2.18×10⁻¹⁸ J(1nf²−1ni²) where ΔE is the change in energy and n is the energy level. 2. Once you had the energy in joules, you could solve for frequency ν using the equation E=hν where h is Planck's constant.
The energy required to ionize magnesium is 738 kJ/mol. What minimum frequency of light is required to ionize magnesium?
v = 1.85 x 10¹⁵ s⁻¹
A proton in a linear accelerator has a de Broglie wavelength of 143 pm. What is the speed of the proton?
v = 2.77 x 10³ m/s You can use the same method to calculate the speed or wavelength of other subatomic particles such as muons and neutrons.
Calculate the frequency of the light emitted when an electron in a hydrogen atom makes a transition from n=5→n=1.
v = 3.16 x 10¹⁵ s⁻¹
Calculate the frequency of the light emitted when an electron in a hydrogen atom makes a transition from n=6→n=5.
v = 4.02 x 10¹³ s⁻¹ You may have noticed that the frequency of the light emitted for the transition from n=4 to n=3 calculated in Part A is larger than the value calculated here for the transition from n=6 to n=5. This is because the energy levels get closer together as n increases.
Calculate the frequency of the light emitted when an electron in a hydrogen atom makes a transition from n=5→n=4.
v = 7.40 x 10¹³ s⁻¹ The frequency of the light emitted is proportional to the energy difference between the orbitals in the transitions. As n increases, the energy levels become closer together such that the energy difference is smaller, corresponding to a lower frequency.
What does each symbol represent? v = c/λ
v = frequency c = speed of light λ = wavelength
Calculate the wavelength. 835.6 MHz (common frequency used for cell phone communication). Express your answer in meters using four significant figures.
λ = 0.3588 m The wavelength is inversely proportional to the frequency. The frequency of such radio waves determines the range of the signal. This is why AM radio has a longer range than FM radio.
Calculate the wavelength. 103.1 MHz (typical frequency for FM radio broadcasting). Express your answer in meters using four significant figures.
λ = 2.908 m 1. To convert a value from frequency in MHz to wavelength in m, start by converting the value to Hz using the conversion factor 10⁶ Hz/1 MHz. 2. Since 1 Hz = 1 s⁻¹, you can now substitute this value into the equation λ = c/ν, where c is the speed of light and ν is the frequency.
Calculate the wavelength. 1070 kHz (typical frequency for AM radio broadcasting). Express your answer in meters using four significant figures.
λ = 280.2 m 1. To convert a value from frequency in kHz to wavelength in m, start by converting the value to Hz using the conversion factor 10³ Hz/1 kHz. 2. Since 1 Hz = 1 s⁻¹, you can now substitute this value into the equation λ = c/ν, where c is the speed of light and ν is the frequency.
What does each symbol represent? λ = h / mv
λ = wavelength h = Planck's constant m = electron mass v = velocity
n=4→n=3 Express the frequency in inverse seconds.
ν¹ = 1.60×10¹⁴ s⁻¹ To calculate the frequency, you should have started by using the equation ΔE=−2.18×10⁻¹⁸ J(1/n₂ƒ−1n²i) where ΔE is the change in energy and n is the energy level. Once you had the energy in joules, you could solve for frequency ν using the equation E=hν where h is Planck's constant.
Probabilty Density
ψ² = probability/unit volume Likelihood of finding an electron at that point in space
The threshold frequency is reached when the energy of the photon is equal to ___.
∅ (phi)
Using the data in the figures above calculate ΔE for the reaction Na(g)+Cl(g)→Na+(g)+Cl−(g)
∆E = 147 kJ/mol
Energy Difference Between the Two Levels n(initial) and n(final)
∆E = E(f) - E(I) OR ∆E = (-2.18 x 10⁻¹⁸ J (1/n²f)) - (-2.18 x 10⁻¹⁸ J (1/n²i)) OR ∆E = -2.18 x 10⁻¹⁸ J (1/n²f - 1/n²i)
What does each part represent? ∆E = -2.18 x 10⁻¹⁸ J (1/n²f - 1/n²i)
∆E = energy difference between levels - 2.18 x 10⁻¹⁸ = Rydberg Constant for Hydrogen n²f = final level n²i = initial level
What does each symbol represent? (∆x)(m∆v) ≥ h/4π
∆x = the uncertainty in position ∆v = the uncertainty in velocity m = mass of the particle h = Planck's constant
