Pauli exclusion principle states that no two electrons in the same atom can have the same set of four quantum numbers identical.
Pauli exclusion principle states that in a single atom no two electrons will have an identical set or the same quantum numbers (n, l, ml, and ms). In simpler words, every electron should have or be in its own unique state (singlet state).
Features of Pauli’s exclusion principle
- Only two electrons can occupy the same orbital.
- The two electrons that are present in the same orbital must have opposite spins or it should be antiparallel.
Which kind of particles obey Pauli’s exclusion principle?
Pauli Exclusion Principle does not only apply to electrons. It applies to other particles of half-integer spin such as fermions. It is not relevant for particles with an integer spin such as bosons which have symmetric wave functions.
- All fermions including neutrons and protons (derived particles) obey the Pauli exclusion principle.
- Bosons, which have integer values of spin do not obey the Pauli exclusion principle. Photons, gravitons, gluons are an example of bosons.