Hund's theorem

Hund's theorem, also known as Hund's rule, describes how electrons occupy orbitals in atoms. It states that when electrons are placed in orbitals of the same energy, they will first fill the orbitals singly, with parallel spins, before pairing up. This arrangement minimizes repulsion between electrons and helps maximize the overall stability of the atom. In simple terms, it's like how people prefer to sit alone rather than share a seat until necessary. This rule plays a crucial role in determining the chemical properties and behaviors of elements.