Question

The filling of degenerate orbitals by electrons is governed by :

• A. Pauli's exclusion law
• B. Hund's rule
• C. Af-bau principle
• D. All of the above

Answer 1

The correct option is D All of the above

The filling of degenerate orbitals by an electron is governed by following:

1) Af-bau principle:

This principle states that electron is added one by one to various orbitals is increasing the order of their energy starting with the lowest energy.

$1s<2s<3s<3p<4s<3\alpha$.............

2) Pauli's exclusion principle:

According to this,"no two electrons in an atom will have the same value of all quantum numbers".

3) Hund's Rule:

According to this rule, electron pairing in $p,\alpha$ orbital cannot occur until each orbital of a given subshell contains one electron each or is singly occupied.