Question

define paulis exclusion principle

Answer 1

Pauli's exclusion principle states that in an atom no two electrons can have identical four electronic quantum numbers.

Answer 2

Pauli Exclusion Principle.

The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers.

As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.