exothermic An exothermic reaction releases energy
(heat) to its surroundings.
face-centered unit cell The face-centered unit cell
has particles at the corners and one in the center
of each face of the cube, but not in the center of
the cube.
First Law of Thermodynamics The First Law of
Thermodynamics states that the total energy of
the universe is constant.
formation constant The formation constant is the
equilibrium constant for the formation of a
complex ion from a metal ion and ligands.
frequency The frequency, ν, is defined as the
number of waves that pass a point per second.
functional groupFunctional groups are reactive
groups on a compound that react in a characteristic
way no matter what the rest of the molecule
consists of.
galvanic (voltaic) cells Galvanic (voltaic) cells are
electrochemical cells that produce electricity by
a redox reaction.
gamma emission Gamma emission is a radioactive
decay process in which high-energy, short-
wavelength photons that are similar to X-rays are
given off.
gas A gas is a state of matter that has neither defi-
nite shape nor volume.
Gay-Lussac’s law Gay-Lussac’s law describes the
direct relationship between the pressure of a gas
and its Kelvin temperature, if the volume and
amount are held constant.
Gibbs free energyThe Gibbs free energy (G) is
a thermodynamic function that combines the
enthalpy, entropy, and temperature. ΔGis the best
indicator of whether or not a reaction will be
spontaneous.
Graham’s law Graham’s law says that the speed of
gas diffusion (mixing of gases due to their kinetic-
energy) or effusion (movement of a gas through
a tiny opening) is inversely proportional to the
square root of the gases’ molecular mass.
ground state The ground state of an atom is the
lowest energy state that the electron can occupy.
groups Groups (families) are the vertical columns
on the periodic table.
half-life The half-life, t1/2, is the amount of time
that it takes for a reactant concentration to
decrease to one-half its initial concentration.
halogensHalogens are in Group 17 on the periodic
table.
heat capacityHeat capacity is the quantity of heat
needed to change the temperature by 1 K.
heat of vaporization The heat of vaporization is the
heat needed to transform a liquid into a gas.
Henderson–Hasselbalch equation The Henderson–
Hasselbalch equation can be used to calculate the
pH of a buffer.
Henry’s law The solubility of a gas will increase with
increasing partial pressure of the gas.
Hess’s law Hess’s law states that if a reaction occurs
in a series of steps, then the enthalpy change for
the overall reaction is simply the sum of the
enthalpy changes of the individual steps.
heterogeneous catalystA heterogeneous catalyst is
a catalyst that is in a different phase or state of
matter from the reactants.
homogeneous catalyst A homogeneous catalyst is
a catalyst that is in the same phase or state of
matter as the reactants.
Hund’s ruleHund’s rule states that electrons are
added to the orbitals, half filling them all before
any pairing occurs.
hybrid orbitalsHybrid orbitals are atomic orbitals
formed as a result of the mixing of the atomic
orbitals of the atoms involved in a covalent bond.
hydrocarbonsHydrocarbons are organic com-
pounds containing only carbon and hydrogen.
hydrogen bondingHydrogen bonding is a specific
type of dipole–dipole attraction in which a hydro-
gen atom is polar-covalently bonded to one of the
following extremely electronegative elements:
O, N, or F.
ideal gasAn ideal gas is a gas that obeys the five pos-
tulates of the Kinetic Molecular Theory of Gases.
ideal gas equation The ideal gas equation relates
the temperature, volume, pressure, and amount of
a gas, and has the mathematical form of PV=nRT.
indicatorsIndicators are substances that change their
color during a titration to indicate the end point.
inert (inactive) electrode An inert (inactive) elec-
trode is a solid conducting electrode in an electro-
chemical cell that does not take part in the redox
reaction.
inner transition elements The inner transition
elements are the two horizontal groups that
have been pulled out of the main body of the
periodic table.
integrated rate law The integrated rate law relates
the change in the concentration of reactants or
products over time.Glossary 361