Lecture Notes on Molecular Orbital Theory

Vocabulary flashcards on key concepts from lecture notes on molecular orbital theory, including valence electrons, bond order, paramagnetism, diamagnetism, and heteronuclear diatomics.

Valence Electrons

The highest energy electrons in an atom, chemically accessible and focus of Lewis Theory.

Core Orbitals

Inner orbitals (e.g., 1s) that remain largely atom-centered and act as a screen for valence electrons; too low in energy to interact effectively with valence orbitals.

Bond Order

Indicates bond strength; calculated as (# bonding electrons - # antibonding electrons) / 2.

Paramagnetic

Substances with unpaired electrons that are attracted to a magnetic field.

Diamagnetic

Substances with all electrons paired, showing no attraction to a magnetic field.

Zeff (Effective Nuclear Charge)

The net positive charge experienced by an electron in a multi-electron atom; calculated as Z (number of protons) - S (shielding constant).

Orbital Mixing

The interaction between s and p orbitals, which can change the order of energy levels in molecular orbitals (e.g., in N2).

Heterodiatomics

Molecules composed of two different atoms, requiring consideration of the relative energies of the atomic orbitals.