moles
unit of measurement represented by "n"
molar mass
the mass of one mole of a pure substance
periodic table
an arrangement of elements in which the elements are separated into groups based on a set of repeating properties
avogadro's number
number of representative particles in a mole, 6.02 X 10^23
atoms
smallest unit of matter
isotopes
Atoms of the same element that have different numbers of neutrons
average atomic mass
weighted average of the atomic masses for the isotopes of an element
solid
Definite shape and volume
liquid
the state of matter that has a definite volume but not a definite shape
gas
A state of matter with no definite shape or volume
formula units
the lowest whole-number ratio of ions in an ionic compound
empirical formula
a chemical formula showing the ratio of elements in a compound rather than the total number of atoms
homogeneous mixture
A mixture in which substances are evenly distributed throughout the mixture
heterogeneous mixture
A mixture in which different materials can be distinguished easily
chromatography
A laboratory technique used to separate mixtures of molecules
electron configurations
the arrangement of electrons in an atom
dalton's theory
all matter is made up of individual particles called atoms, which cannot be divided
coulomb's law
The relationship among electrical force, charges, and distance: The electrical force between two charges varies directly as the product of the charges and inversely as the square of the distance between them.
the bohr model
model of the atom in which electrons move rapidly around the nucleus in paths called orbits
the aufbau principle
An electron occupies the lowest-energy orbital that can receive it
the pauli exclusion principle
states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins
hund's rule
states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
noble gas shortcut
A shorthand way to write electron configurations. Write the noble gas followed by the rest of the electron configuration that follows the noble gas.
valence electrons
Electrons on the outermost energy level of an atom
core electrons
inner electrons
ionization energy
the energy required to remove an electron from an atom
atomic radius
size of an atom
nuclear charge
the total charge of all the protons in the nucleus
electron
A subatomic particle that has a negative charge
electron repulsion
A repulsive force caused by the similar negative charge of two or more electrons.
ionic radius
Distance from the center of an ion's nucleus to its outermost electron
electronegativity
the ability of an atom to attract electrons when the atom is in a compound
metal
an element that is shiny and that conducts heat and electricity well
nonmetal
an element that conducts heat and electricity poorly
polar covalent bonds
unequal sharing of electrons
nonpolar covalent bonds
equal sharing of electrons
cation
A positively charged ion, smaller than neutral
anion
A negatively charged ion, larger than neutral
dimensional analysis
A way to analyze and solve problems using the units, or dimensions, of the measurements
lewis dot structure
diagram of a molecule using dots to represent valence electrons
VSEPR
Valance Electron Pair Repulsion model / Unshared electron pairs around the central atom
Covalent
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
Ionic
transfer of electrons
metallic bond
a bond formed by the attraction between positively charged metal ions and the electrons around them
resonance
the bonding in molecules or ions that cannot be correctly represented by a single Lewis structure
polarity
Molecules having uneven distribution of charges
dipoles
positive and negative charged ends of a polar covalent molecule
Planck's Constant
6.626 x 10^-34
Wavelength
The distance between two corresponding parts of a wave
Frequency
the number of complete wavelengths that pass a point in a given time
extensive property
a property that depends on the amount of matter in a sample
intensive property
a property that depends on the type of matter in a sample
half life
length of time required for half of the radioactive atoms in a sample to decay
molecular formula
A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms. The real number of atoms/elements needed to form compound.
mole highway
Grams --> Mole : Mass/Molar Mass \n Mole --> Atom : Mole # x 6.02E23 \n Atom --> Mole : Mole #/6.02E23 \n Mole --> Grams : Mass x Molar Mass
heating curve
a diagram that shows the temperature changes and changes of state of a substance as it is heated; Solid melts to liquid, liquid evaporates to gas. Gas condenses to liquid, liquid freezes to solid
Significant Figure Rules
non-zeros are always significant;
zeros between two other sig figs are significant;
all final zeros after the decimal point are significant;
zeros used solely for spacing the decimal point are not significant unless a decimal point is present
alkali metals
Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
alkaline metals
metallic elements in group 2 of the periodic table which are harder than the alkali metals and are also less reactive
halogens
Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive
noble gases
Elements in group 8A of the periodic table. Have no charge and are gases under normal conditions. (Helium, Neon, Argon, Krypton, Xenon, Radon)
octet rule
States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons
octet rule exceptions
-Hydrogen (has only 2) \n -Lithium, Beryllium, and boron (less than 8) \n -all period 3 and below can hold >8
molecular shapes
Linear, Bent (lone pairs) , Trigonal Planar, and Trigonal Pyramidal (lone pair)