Chapter 8 Key Terms

antibonding orbital

molecular orbital located outside of the region between two nuclei; electrons in an antibonding orbital destabilize the molecule

bond order

number of pairs of electrons between two atoms; it can be found by the number of bonds in a Lewis structure or by the difference between the number of bonding and antibonding electrons divided by two

bonding orbital

molecular orbital located between two nuclei; electrons in a bonding orbital stabilize a molecule

degenerate orbitals

orbitals that have the same energy

diamagnetism

phenomenon in which a material is not magnetic itself but is repelled by a magnetic field; it occurs when there are only paired electrons present

homonuclear diatomic molecule

molecule consisting of two identical atoms

hybrid orbital

orbital created by combining atomic orbitals on a central atom

hybridization

model that describes the changes in the atomic orbitals of an atom when it forms a covalent compound

linear combination of atomic orbitals

technique for combining atomic orbitals to create molecular orbitals

molecular orbital

region of space in which an electron has a high probability of being found in a molecule

molecular orbital diagram

visual representation of the relative energy levels of molecular orbitals

molecular orbital theory

model that describes the behavior of electrons delocalized throughout a molecule in terms of the combination of atomic wave functions

node

plane separating different lobes of orbitals, where the probability of finding an electron is zero

overlap

coexistence of orbitals from two different atoms sharing the same region of space, leading to the formation of a covalent bond

paramagnetism

phenomenon in which a material is not magnetic itself but is attracted to a magnetic field; it occurs when there are unpaired electrons present

pi bond (π bond)

covalent bond formed by side-by-side overlap of atomic orbitals; the electron density is found on opposite sides of the internuclear axis

s–p mixing

change that causes σ_p orbitals to be less stable than π_p orbitals due to the mixing of s and p-based molecular orbitals of similar energies.

sigma bond (σ bond)

covalent bond formed by overlap of atomic orbitals along the internuclear axis

sp hybrid orbital

one of a set of two orbitals with a linear arrangement that results from combining one s and one p orbital

sp² hybrid orbital

one of a set of three orbitals with a trigonal planar arrangement that results from combining one s and two p orbitals

sp³ hybrid orbital

one of a set of four orbitals with a tetrahedral arrangement that results from combining one s and three p orbitals

sp³d hybrid orbital

one of a set of five orbitals with a trigonal bipyramidal arrangement that results from combining one s, three p, and one d orbital

sp³d ² hybrid orbital

one of a set of six orbitals with an octahedral arrangement that results from combining one s, three p, and two d orbitals

valence bond theory

description of bonding that involves atomic orbitals overlapping to form σ or π bonds, within which pairs of electrons are shared

π bonding orbital

molecular orbital formed by side-by-side overlap of atomic orbitals, in which the electron density is found on opposite sides of the internuclear axis

π* bonding orbital

antibonding molecular orbital formed by out of phase side-by-side overlap of atomic orbitals, in which the electron density is found on both sides of the internuclear axis, and there is a node between the nuclei

σ bonding orbital

molecular orbital in which the electron density is found along the axis of the bond

σ* bonding orbital

antibonding molecular orbital formed by out-of-phase overlap of atomic orbital along the axis of the bond, generating a node between the nuclei