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Chapter 1
Copyright © 2017 Pearson Education, Inc.
mass number
the number of protons plus the number of neutrons in an atom.
molecular mass
the sum of the atomic masses of all the atoms in the molecule.
molecular orbital
an orbital associated with a molecule that results from the combination of atomic
orbitals.
molecular orbital (MO)
a theory that describes a model in which the electrons occupy orbitals as they do in
theory
atoms but the orbitals extend over the entire molecule.
node
a region within an orbital where there is zero probability of finding an electron.
nonbonding electrons
valence electrons not used in bonding.
nonpolar covalent bond
a bond formed between two atoms that share the bonding electrons equally.
octet rule
a rule that states that an atom will give up, accept, or share electrons to achieve a
filled outer shell (or an outer shell that contains eight electrons) and no electrons of
higher energy. Because a filled second shell contains eight electrons, this is known
as the octet rule.
orbital
the volume of space around the nucleus where an electron is most likely to be found.
orbital hybridization
mixing of atomic orbitals.
organic compound
a compound that contains carbon.
Pauli exclusion principle
a principle that states that no more than two electrons can occupy an orbital and
that the two electrons must have opposite spin.
pi
(
P
)
bond
a bond formed as a result of side-to-side overlap of
p
orbitals.
polar covalent bond
a bond formed between two atoms that do not share the bonding electrons equally.
potential map
a map that allows you to see how electrons are distributed in a molecule.
(electrostatic potential map)
proton (hydrogen ion)
a positively charged hydrogen ion.
quantum mechanics
the use of mathematical equations to describe the behavior of electrons in atoms or
molecules.
radical (free radical)
a species with an unpaired electron.
sigma
(
S
)
bond
a bond with a symmetrical distribution of electrons about the internuclear axis.
single bond
a pair of electrons shared between two atoms.
skeletal structure
shows the carbon–carbon bonds as lines but does not show the carbons or the
hydrogens that are bonded to the carbons.