Source: wikibot/pauli-exclusion-principle

= Pauli exclusion principle
{wiki=Pauli_exclusion_principle}

The Pauli exclusion principle is a fundamental principle in quantum mechanics, formulated by physicist Wolfgang Pauli in 1925. It states that no two fermions (particles with half-integer spin, such as electrons, protons, and neutrons) can occupy the same quantum state within a quantum system simultaneously. In the context of atomic structure, this principle explains why electrons in an atom fill available energy levels in a specific way.