Question

Select the correct options according Hund's rule and Pauli exclusion principle:

• A. Both I and II
• B. Both II and III
• C. Both I and III
• D. Both III and IV

Answer 1

The correct option is D Both III and IV

According to the Pauli exclusion principle, no two-electron in an atom can have the same set of four quantum numbers.

Hund's rule state that the pairing of electrons in the orbital of a particular sub-shell (p, d or f) does not take place until all the orbitals of the subshell are singly filled.

Option I and II do not follow Hund's rule and Paulis exclusion principle.

Hence, option $D$ is correct.