The rule of Hund applies to the distribution of the electron S in the electronic Configuration of the Atome S.

When several orbital belongs to the same underlayer (even energy), the electrons tend to occupy the maximum of orbital before saturating each one of them, thus the total Spin of an atom is always maximum.

See too

• Principle of exclusion of Pauli
• Rule of Klechkowsky
• Rule of the byte
• Rule of the duet
• electronic Configuration