Chemical Bonding II: Valence Bond and Molecular Orbital Theory

These flashcards cover key terms and definitions related to Chemical Bonding, specifically focusing on Valence Bond Theory and Molecular Orbital Theory.

Paramagnetic

A material that has unpaired electrons and is attracted to a magnetic field.

Valence Bond Theory

A theory that describes the formation of chemical bonds through the overlap of atomic orbitals.

Hybridization

The mixing of atomic orbitals to produce new hybrid orbitals suitable for the pairing of electrons to form chemical bonds.

Sigma bond (σ bond)

A covalent bond formed by the direct overlap of atomic orbitals.

Pi bond (π bond)

A covalent bond formed by the sideways overlap of p orbitals.

Molecular Orbital Theory

A theory that describes the electronic structure of molecules in terms of molecular orbitals that belong to the whole molecule.

Bond Order

A measure of the strength of a bond, calculated as the difference between the number of bonding electrons and antibonding electrons, divided by two.

Electron Delocalization

A concept in molecular orbital theory where electrons are distributed across multiple atoms, rather than being confined to a single bond between atoms.

Lone pair

A pair of valence electrons that are not shared with another atom.

Resonance

The concept that some molecules can be represented by multiple valid Lewis structures, indicating the delocalization of electrons.

Lewis structure

A diagram that represents the bonding in a molecule and the arrangement of electrons.

Atomic Orbital

A region around the nucleus of an atom where there is a high probability of finding electrons.

Unhybridized orbital

An atomic orbital that has not been involved in hybridization and retains its original shape and energy.

Tetrahedral geometry

A molecular geometry with four bonded atoms surrounding a central atom, resulting in bond angles of approximately 109.5°.

Trigonal planar

A molecular geometry where three atoms are arranged around a central atom in a flat plane with bond angles of 120°.

Octahedral geometry

A molecular geometry where six atoms are arranged around a central atom, resulting in bond angles of 90°.

Antibonding Molecular Orbital

A molecular orbital that has higher energy than the atomic orbitals that combine to form it and is associated with electron density outside the internuclear axis.

Bonding Molecular Orbital

A molecular orbital that has lower energy than the atomic orbitals that combine to form it and is associated with electron density between the nuclei.

Hybrid orbital

An orbital that results from the hybridization of atomic orbitals to accommodate bonding in a molecule.

Degenerate orbitals

Orbitals that have the same energy level.