Friedrich Hund

Hund's Rules for Filling Degenerate Orbitals (Friedrich Hund)

Electrons fill degenerate orbitals according to rules first stated by Friedrich Hund. Hund's rules can be summarized as follows.

1. One electron is added to each of the degenerate orbitals in a subshell before two electrons are added to any orbital in the subshell.

2. Electrons are added to a subshell with the same value of the spin quantum number until each orbital in the subshell has at least one electron.

Hund's rules can be understood by assuming that electrons try to stay as far apart as possible to minimize the force of repulsion between these particles.