Question

difine pauli exclusion principle why is it called exclusion principle​

Answer 1

Answer:

Pauli exclusion principle states that in a single atom no two electrons will have an identical set or the same quantum numbers (n, l, m, and s). To put it in simple terms, every electron should have or be in its own unique state (singlet state). There are two salient rules that the Pauli Exclusion Principle follows:

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.

It is called exclusion principle because according to this principle, if one electron in an atom has same particular values for the four quantum numbers, then all the other electrons in that atom are exclude from having the same set of values.