Hund rules

Hund's rules, proposed by physicist Friedrich Hund, describe the electronic configuration of atoms. These rules are crucial for understanding how electrons fill atomic orbitals, particularly when multiple orbitals have the same energy.

The rules state that:
* Electrons will occupy separate orbitals within a subshell before pairing up.
* When occupying separate orbitals, electrons will have parallel spins.

This arrangement minimizes electron-electron repulsion and leads to a lower energy state for the atom. These principles are fundamental to quantum mechanics and explain the observed patterns in atomic spectra and chemical bonding. The Pauli exclusion principle, which states that no two electrons in an atom can have the same set of quantum numbers, is also integral to understanding electron configurations.123