Question

In a ground state atom of Br how many electrons total will have the quantum number l=2?

Please provide explanation.

Answer 1

Pauli Exclusion principle states that no two electrons can have the same quantum numbers. Each electron has a specific set of unique quantum numbers.

The electronic configuration of bromine atom is;

$1s^22s^22p^63s^23p^64s^23d^{10}4p^5$

It's principal quantum number is $4.33$

Quantum number $l=2$ corresponds to d level only

The total number of orbitals $=4*10$ electrons

$=40$ electrons.