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Chemistry: Atoms First

Key Terms

Chemistry: Atoms FirstKey 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 σp orbitals to be less stable than πp 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
sp3d2 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
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