Aleks Placement Test: Chemistry
Ethane
2 carbon
molecular compound
2 or more DIFFERENT atoms -covalently bonded
molecular element
2 or more atoms of the SAME element
Pentane
5 carbon
Wave-Particle Duality of Light
Light sometimes acts like a particle and sometimes like a wave
Dilution
M1V1 = M2V2
Ionic Bonds
Metal looses the electron and nonmetal gains it; the farther apart they are on the table the more likely it's ionic
Electromagnetic Spectrum
The range of wavelengths or frequencies over which electromagnetic radiation extend
Molecule
The smallest particle that has any of the properties of a compound
Plasma
The state of matter with the highest energy; it uses ionization instead of bonds
Bose-Einstein Condensate
The state of matter with the lowest energy; basically a very cold solid
Half-Life
The time required for half of the original sample of nuclei to decay; each radioactive nucleus of the same element has the same half-life; the shorter the half-life, the more likely a nucleus will decay
Combination Reaction
Two or more compounds form to make one compound.
Mixture
Two or more substances that are together but not bonded
Precipitation Reaction
Two solutions of soluble salts are mixed, resulting in an insoluble solid (precipitate) forming.
Atoms and Colors
When an atom is excited by energy it gives off its own characteristic colors of light
Visible Light
White light is passed through a prism and creates all visible colors; each color has its own frequency and wavelength
Zinc
Zn(2+)
Hypo (Cl & Br & I) ite
__O (-)
(Cl & Br & I) ite
__O2 (-)
(Cl & Br & I) ate
__O3 (-)
Per (Cl & Br & I) ate
__O4 (-)
_______ite
_______ous acid
______ate
______ic acid
Hydrogen Bond
a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other (N, O, F)
Bright Line Spectrum
a.k.a. emission spectrum; occurs due to the energy an electron gives off as it travels from high to low energy; fireworks
Ionic Bond
between metal and nonmetal
Covalent Bond
between two nonmetals
charge: 0 mass :1
charge and mass of a neutron
charge: +1 mass: 1
charge and mass of a proton
charge: -1 mass: 0
charge and mass of electron
mixture
contains many different components
pure substance
contains only one component has characteristic properties
g atoms given x 1 mol/mass of element finding
conversion to find moles
no
does the composition of a compound ever change?
Activation Energy Graph
download from reactants to loop other is either energy absorbed or released
condensation
gas --> liquid =
deposition
gas --> solid
vertical rows
groups
7
hepta
degree kelvin given - 273
how to find celsius
273 + degree of celsius given
how to find kelvin
dipole points toward more electronegative
how to tell electronegativity?
evaporation
liquid --> gas =
freezing
liquid --> solid
What happens with catalyst? <catalyzed reaction>
lowering of activation energy
groups with letter A
main group elements have letter ____
weight of moles x weight of element/1 mole
mole to mass conversion
protons, neutrons
more ______ you have, more _____ you need
positive
move decimal to left, positive or negative?
negative
move decimal to right, positive or negative?
atomic number
number of protons =
dipole dipole
occur between polar molecules
5
penta
horizontal rows
periods
octet rule
predicts preferred bonding patterns for many main group non metals
Gay Lussac Law
pressure and temperature P1/T1 = P2/T2
Boyle's Law
pressure and volume P1V1 = P2V2
Polymerization
process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.
lewis dot symbol
shows the valence e- for an element
sublimation
solid --> vapor
hydrogen, dipole dipole, dispersion
strongest to weakest forces
4
tetra
henrys law
the solubility of a gas in a liquid is proportional to the pressure of the gas above that liquid
mass number
total number of proton and neutrons in the nucleus =
Methane
1 carbon
Propane
3 carbon
Speed of Light
3.00•10^8m/s
Butane
4 carbon
Speed
How fast a wave travels in a given distance
Atomic Radius
The radius of an atom; decreases as you move left to right and increases as you move top to bottom
Covalent Bonds
Atoms are sharing electrons; the closer the elements are the more likely it's covalent
Borate
BO3(3-)
Polar Covalent Bonding
Bond where electrons are shared unequally
Bromate
BrO3(-)
Acetate
C2H3O2(-)
Oxalate
C2O4(2-)
Cyanide
CN(-)
Carbonate ?
CO3(2-) insoluble
Cadmium
Cd(2+)
Cobalt
Co(2+) & Co(3+)
Dichromate
Cr2O7(2-)
Chromate
CrO4(2-)
Copper
Cu(+) & Cu (2+)
Combustion Reaction
CxHy + O2 -> CO2 + H2O
IMF Scale
Dipersion < Dipoles < Hydrogen
Compound
Elements combine to form chemical compounds
Celcius & Fahrenheit
F=1.8C+32
Iron
Fe(2+) & Fe (3+)
Molar Mass
Found by summing the masses of the component atoms
Strong Acid (6)
HCl HBr HI HNO3 H2SO4 HClO4
Neutralization Reaction
Acid + Base -> Salt + H2O
Organic Acid
Acid that contains a carbon atom
Diprotic Acid
Acid that has 2 hydrogens to donate
Triprotic Acid
Acid that has 3 hydrogens to give
Oxyacid
Acid that has an oxygen
Silver
Ag(+)
Neutralisation Reaction
An acid and a base react with each other. Generally the product of this reaction is a salt and water.
Cation
An atom that looses electrons and has a positive charge; metals
Element
Any substance that contains only one kind of an atom
Matter
Anything that has mass and takes up space; made of atoms
Arsenite
AsO3(3-)
Arsenate
AsO4(3-)
Periodic Trends (1) Electronegativity (2) Ionization Energy (3) Electron Affinity (4) Atomic Radius
(1) & (2) & (3) increase towards top right (4) increase towards bottom left
polar
-electrons are not shared equally
nonpolar
-even electron distribution
dipole dipole forces
-stronger attraction -only polar molecules
dispersion forces
-weak attraction -non polar and polar molecules
Celcius & Kelvin
0 C = 273.15 K K= C+273.15
6.022 x 10^23
1 mole =
Hexane
6 carbon
Avogadro's number
6.022 X 10 ^ 23
(F-32) x 5/9
= celsius
c x 9/5 +32
= farenheit
polar
> 0.4 means it is
Polar Covalent Bond
A bond between 2 nonmetal atoms that have different electronegativities and therefore have unequal sharing of the bonding electron pair.
Nonpolar Covalent Bond
A bond between 2 nonmetal atoms that have the same electronegativity and therefore have equal sharing of the bonding electron pair.
Decomposition Reaction
A complex molecule breaks down to make a simpler one.
Base
A substance that decreases the hydrogen ion concentration in a solution.
Acid
A substance that increases the hydrogen ion concentration of a solution.
Ionic Compound
Metals often react with nonmetals to form ionic compounds. These compounds are composed of positive and negative ions formed by adding or subtracting electrons from neutral atoms and molecules.
Manganese
Mn(2+) & Mn(3+)
Permanganate
MnO4(-)
Ammonium
NH4(+) compounds are soluble
Nitrite
NO2(-)
Nitrate ?
NO3(-) compounds are soluble
Covalent Compound
Nonmetals combine with each other to form covalent compounds, which exist as neutral molecules.
Peroxide
O2(2-)
Cyanate
OCN(-)
Hydroxide ?
OH(-) insoluble
Hydrogen Bonding
Occurs between hydrogen and F, N, or O
Displacement Reaction
One element trades places with another element in the compound.
Combustion Reaction
Oxygen combines with a compound to form carbon dioxide and water. These reactions are exothermic, meaning they give off heat.
Phosphite
PO3(3-)
Phosphate
PO4(3-)
Ideal Gas Law
PV = nRT R: 0.08206 L atm / mol K 8.314 J / mol K
Lead
Pb(2+) & Pb(4+)
PH Scale
Ranges from 1 to 14, with 7 considered to be neutral. *pH less than 7 is said to be acidic *pH greater than 7 are basic or alkaline.
Lewis Structures
Represent the valence electrons
Thiosulfate
S2O3(2-)
Thiocynate
SCN(-)
Sulfite
SO3(2-)
Sulfate ?
SO4(2-) most are soluble -> except Ba Hg Pb
Tin
Sn(2+) & Sn(4+)
Five states of Matter
Solids, liquids, gases, plasmas, and Bose-Einstein condensates
Pure Substance
Substance that contains only one kind of compound
Avogadro's Law
volume and number of moles V1 / n1 = V2 / n2
Charles Law
volume and temperature V1/T1 = V2/T2
exchange of gases between the lungs and the blood
what does henrys law explain?
london dispersion
what force exists between ALL particles?
F, O, N
what must hydrogen be bonded to to be considered hydrogen bonding?
Neutron Number
Atomic Mass - Atomic Number
Characteristics of Metals
- Malleable - Ductile - Conductive - Lustrous
Decane
10 carbon
Planck's Constant
6.626•10^-34 Joules/hertz
Heptane
7 carbon
Octane
8 carbon
Nonatne
9 carbon
Photon
A light particle
Wave-Mechanical Model of the Atom
A model of the atom in which the orbitals are nothing like orbits
Plum Pudding Model
A model of the atom that depicts a sphere of positive charge with electrons scattered throughout
Radioactive
A nucleus that spontaneously decomposes, forming a different nucleus and producing one or more particles; alpha, beta, and gamma ray
Atomic Mass
A number that tells the number of protons and neutrons in an atom
Elements
A pure substance that contains only one type of atom
Atomic Orbital
A region around the nucleus of an atom where an electron with a given energy may be found 90% of the time; 4 types: s, p, d, and f
Pauli Exclusion Principle
A rule that states that each electron has its own unique set of quantum numbers and that two electrons with the same spin cannot occupy the same orbital and that an orbital can only hold two electrons
Gas
A state of matter with no bonds
Solid
A state of matter with strong bonds
Liquid
A state of matter with weak bonds
Atomic Number
A unique number to each element that tells the number of protons and the number of electrons if the atom is neutral
Acids
Always start with hydrogen; donate a proton in a solution
Anion
An atom that gains electrons and has a negative charge; nonmetals
Isotope
An atom that has changed its number of neutrons
Ion
An atom that has gained or lost electrons
Law of Constant Composition
Atoms of one element can combine with other elements to form compounds; a given compound always has the same relative numbers and types of atoms
Percent Abundance Equation
Average Mass = (%)•(Mass of Isotope A) + (%)•(Mass of Isotope B) +...
Atoms
Basic unit of matter which cannot be broken down and contain mostly empty space; contains three parts: the electron, proton, and neutron
Continuous Spectrum
Broken bands of colored light
Speed of Light Equation
C = w•f C is the speed of light w is wavelength in meters f is frequency in hertz
Ernest Rutherford
Conducted an experiment in which he shot alpha particles at gold foil; roved there was a small, dense nucleus with a positive charge and that protons are positive
J.J. Thomson
Discovered electrons and protons and developed the plum pudding model of an atom
Energy using Planck's Constant
E = h•f E is energy h is Planck's constant f is frequency in hertz
Hund's Rule
Each suborbital will fill with one electron before accepting a second electron
Kernel Structure
Electron configuration shorthand 1. Find the noble gas that comes before the element 2. Write the gas in brackets 3. Determine energy level and orbital you are starting on 4. Follow the energy pyramid
Valence Electrons
Electrons on outer most orbital; always the highest energy 's' and 'p' orbital
Percent Abundance
Elements exist naturally in different isotopes, to the atomic mass listed on the table is an average
Metals
Elements located on the left side of the periodic table that want to lose electrons
Nonmetals
Elements located on the right side of the periodic table that want to gain electrons
Metalloids
Elements placed in a stair-step line between metals and nonmetals; they have characteristics of both
Diatomic Molecules
Elements that occur in pairs in their natural state; hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine
Robert Boyle
First to define an element; any substance is a substance unless it can be broken down
Heisenberg Uncertainty Principle
It is impossible to know the exact position and momentum of an electron at the same time
Alpha Particle
One type of radioactive particle; it is a essentially a helium nucleus; when this type of particle is released, the mass of the atom is conserved and so is the atomic number
Gamma Ray
One type of radioactive particle; it is a high energy photon of light and is used to release excess energy; the atom is not changed at all
Beta Particle
One type of radioactive particle; it is essentially an electron; when this type of particle is released, the atomic mass is conserved and the atomic number gains one (a neutron is changed to a proton)
Node
Point on a wave where the wave returns to the zero line; a crest or trough is trapped between the two points
S
Quantum number that tells how an electron spins in an orbital
M
Quantum number that tells us the orientation of the orbital in space
Alcohols
Subtract a hydrogen and add a -OH group; add ol to end of name
Electronegativity
The ability of a molecule to attract electrons to it; increases as you move left to right in the table and decreases as you move top to bottom; fluorine is the hardest
Conductive
The ability to allow heat or electricity to pass through an object
Malleable
The ability to be molded into shapes
Ductile
The ability to be pulled into wire
Lustrous
The ability to be shiny
Wavelength
The distance between the crests of a wave; symbol is lambda
Oxidation State
The electrons an element will gain or lose in order to become stable (8 electrons)
Ionization Energy
The energy needed to rip off an electron; increases as you move left to right and decreases as you move top to bottom
Amplitude
The height of a crest or trough; crest to the zero line; absolute value
Crest
The highest point of a wave
Trough
The lowest point of a wave
Electrons
The negatively charged particle in an atom; circles around the nucleus in the electron cloud
Neutron
The neutral particle in an atom; it has no charge and is located in the nucleus
Frequency
The number of waves that pass through a point in a given time; symbol is nu
L
The orbital quantum number; tells us the shape of the orbital (s,p,d,f)
F Orbital
The orbital with the highest energy; it has seven orbitals and can hold 14 electrons
S Orbital
The orbital with the lowest energy; it has one orbital and can hold two electrons
D Orbital
The orbital with the second highest energy; it has five orbitals and can hold ten electrons
P Orbital
The orbital with the second lowest energy; it has three orbitals and can hold six electrons
Proton
The positively charged particle in an atom; located in the nucleus; determine the element
N
The principal quantum number; tells us which energy level an electron is found in, the maximum number of electrons that can be found in one energy level, and the size of an electron cloud
Quantum Theory for an Atom
The probability of finding electrons in certain regions of an atom is described by orbitals
Compound
Two or more elements that are chemically bonded; includes ionic and covalent
John Dalton
Used and combined previous ideas to discuss the atom; elements are made of atoms; all atoms of an element are identical; atoms of different elements are different; law of constant composition; atoms are invisible
Dark Line Spectrum
a.k.a. absorption spectrum; occurs due to the energy that an electron gains as it travels from low to high energy