Hund's rules

Hund's rules are guidelines used to determine the ground state of an atom's electrons in its energy levels. They state that when electrons occupy orbitals of equal energy, they will first fill each orbital singly with parallel spins before pairing up. This minimizes electron-electron repulsion and leads to a more stable arrangement. In essence, electrons prefer to spread out in separate orbitals rather than pair up in the same orbital. This principle helps explain the magnetic properties of atoms and influences their chemical behavior.