Question

about all four Principal Quantum numbers

Answer 1

The four quantum numbers n, ℓ, m, and s specify the complete and unique quantum state of a single electron in an atom, called its wave function or orbital. Two electrons belonging to the same atom cannot have the same values for all four quantum numbers, due to the Pauli exclusion principle.

Answer 2

there are four principal quantum no
1. n principal quantum no. which takes values 0,1,2,3....
2. L orbital quantum number which takes values +_1,+_2+-.....
3 m magnetic quantum no. which takes values 0,+-L
4 S spin quantum no which takes values +_ half.