GLOSSARY
absolute zero Absolute zero is 0 K and is the point
at which all molecular motion ceases.
acidic A solution whose pH is lessthan 7.00 is said
to be acidic.
acids Acids are proton (H+) donors.
acid dissociation constant (Ka)The acid dissociation
constant is the equilibrium constant associated
with a weak acid dissociation in water.
activation energy Activation energy is the mini-
mum amount of energy that must be supplied to
initiate a chemical reaction.
activity series for metals The activity series lists
metals in order of decreasing ease of oxidation.
actual yieldThe actual yield is the amount of prod-
uct that is actually formed in a chemical reaction.
alkali metals Alkali metals are in Group 1 on the
periodic table.
alkaline earth metals Alkaline earth metals are in
Group 2 on the periodic table.
alkanes Alkanes are hydrocarbons that contain only
single covalent bonds within the molecule.
alkenes Alkenes are hydrocarbons that contain
a carbon-to-carbon double bond.
alkynes Alkynes are hydrocarbons that contain
a carbon-to-carbon triple bond.
alpha particleAn alpha particle is essentially a helium
nucleus with two protons and two neutrons.
amorphous solids Amorphous solids are solids that
lack extensive ordering of the particles.
amphotericAmphoteric substances will act as either
an acid or a base, depending on whether the other
species is a base on an acid.
amplitudeAmplitude is the height of a wave and is
related to the intensity (or brightness for visible
light) of the wave.
amuAn amu is^1 ⁄ 12 the mass of a carbon atom that
contains 6 protons and 6 neutrons (C-12).
angular momentum quantum number (l) The
angular momentum quantum number is
the quantum number that describes the shape of
the orbital.
anionsAnions are negatively charged ions.
anode The electrode at which oxidation is taking
place is called the anode.
anode compartment The anode compartment is
the electrolyte solution in which the anode is
immersed.
aqueous solutionAn aqueous solution is a solution
in which water is the solvent.
atomic number (Z)The atomic number of an
element is the number of protons in the nucleus.
atomic orbitalThe atomic orbital is the region of
space in which it is most likely to find a specific
electron in an atom.
atomic solidsIn atomic solids, individual atoms are
held in place by London forces.
Aufbau principleThe Aufbau principle states that
the electrons in an atom fill the lowest energy
levels first.
Avogadro’s law Avogadro’s law states that there is
a direct relationship between the volume and the
number of moles of gas.
Avogadro’s number Avogadro’s number is the
number of particles (atoms or molecules or ions)
in a mole and is numerically equal to 6.022 × 1023
particles.
barometer A barometer is an instrument for
measuring atmospheric pressure.
base dissociation constant, Kb The base dissocia-
tion constant is the equilibrium constant asso-
ciated with the dissociation of a weak base in
water.
basesBases are defined as proton (H+) acceptors.
basicA solution whose pH is greater than 7.00 is
called basic.
beta particleA beta particle is an electron.
bimolecular reactionsBimolecular reactions are
chemical reactions that involve the collision of
two chemical species.
binary compoundsBinary compounds are com-
pounds that consist of only two elements.
body-centered unit cellA body-centered unit cell
has particles located at the corners of a cube and
in the center of the cube.
boilingThe process of going from the liquid state to
the gaseous state is called boiling.
boiling pointThe boiling point (b.p.) is the temper-
ature at which a liquid boils.358