metathesis reactionIn a metathesis reaction two
substances exchange bonding partners.
molality (m) Molality is defined as the moles of
solute per kilogram of solvent.
molar heat capacity The molar heat capacity (C) is
the amount of heat needed to change the tempera-
ture of 1 mole of a substance by 1 K.
molarity (M) Molarity is a concentration term
that represents the moles of solute per liters of
solution.
molar mass The mass in grams of one mole of
a substance.
mole The mole (mol) is defined as the amount of
a substance that contains the same number of
particles as atoms in exactly 12 g of carbon-12.
molecular equation The molecular equation is
an equation in which both the reactants and
products are shown in the undissociated form.
molecular formulaThe molecular (actual) formula
shows which elements are in the compound and
the actual number of atoms of each element.
molecular orbital theoryThe molecular orbital
(MO) theory of covalent bonding proposes that
atomic orbitals combine to form molecular
orbitals that encompass the entire molecule.
molecular solids Molecular solids have their lattices
composed of molecules held in place by London
forces, dipole–dipole forces, and hydrogen bonding.
molecule A molecule is a covalently bonded
compound.
monomers Macromolecules are composed of
repeating units, called monomers.
Nernst equationThe Nernst equation allows the
calculation of the cell potential of a galvanic cell
that is not at standard conditions.
net ionic equationThe net ionic equation is written
by dropping out the spectator ions and showing
only those chemical species that are involved in
the chemical reaction.
network covalent solids Network covalent solids
have covalent bonds joining the atoms together in
an extremely large crystal lattice.
neutralNeutral is 7.00 on the pH scale.
neutralization reactions Neutralization reactions are
acid–base reactions in which an acid reacts with
a base to give a salt and usually water.
noble gases Noble gases are in Group 18 on the
periodic table. They are very unreactive owing to
their filled valence shell.
nonelectrolytesNonelectrolytes are substances that
do not conduct electricity when dissolved in water
or melted.
nonmetals Nonmetals have properties that are
generally the opposite of metals. Some are gases,
are poor conductors of heat and electricity, are
neither malleable nor ductile, and tend to gain or
share electrons in their chemical reactions.
nonpolar covalent bondIn a nonpolar covalent
bond the electrons are shared equally by the two
atoms involved in the bond.
nuclear belt of stabilityThe nuclear belt of stabil-
ity is a plot of the # neutrons versus the # protons
for the known stable isotopes.
nucleus The nucleus is a dense core of positive
charge at the center of the atom that contains
most of the mass of the atom.
octet ruleThe octet rule states that during chemical
reactions, atoms lose, gain, or share electrons in
order to achieve a filled valence shell, to complete
their octet.
orbital An orbital or wave function is a quantum
mechanical mathematical description of the
location of electrons. The electrons in a particular
subshell are distributed among these volumes of
space of equal energies.
order of reactionThe order of reaction is
the exponent in the rate equation that indicates
what effect a change in concentration of that
particular reactant species will have on the
reaction rate.
organic chemistryOrganic chemistry is the study of
the chemistry of carbon.
osmosis Osmosis is the passing of solvent molecules
through a semipermeable membrane.
osmotic pressure The osmotic pressure is
the amount of pressure that must be exerted
on a solution in order to prevent osmosis of
solvent molecules through a semipermeable
membrane.
oxidationOxidation is the loss of electrons.
oxidation numbersOxidation numbers are book-
keeping numbers that allow chemists to do things
like balance redox equations.
oxidizing agentThe oxidizing agent is the reactant
being reduced.
paramagnetismParamagnetism is the attraction of
a molecule to a magnetic field and is due to
unpaired electrons.
pascalThe pascal is the SI unit of pressure.Glossary 363