Question

According to Pauli's exclusion principle the two electrons in the same orbital will have parellel spins.

• A. True
• B. False

Answer 1

The correct option is B False

According to the Pauli's exclusion principle, the two electrons of the same atom cannot have the same four quantum numbers.

In any atom, if $\text{n, l,}{\text{m}}_{\text{l}}$ quantum numbers are the same for two electrons then ${\text{m}}_{\text{s}}$ must be different.

As an orbital can contain a maximum of only two electrons, the two electrons must have opposite spins or anti parallel spins. This means if one is assigned an up-spin (+1/2), the other must be down-spin (-1/2).