Question

Which one of the following violates the octet rule?

• A. $As{F}_5$
• B. $N{F}_3$
• C. $CB{r}_4$
• D. $PC{l}_3$

Answer 1

The correct option is A $As{F}_5$

Arsenic has a noble gas configuration of $\left[Ar\right]4s^{2}3d^{10}4p^3$.

There is an empty $4d$ orbital. These empty orbitals can get involved in the hybridisation process to allow these central atoms to have an expanded octet. Hence, $As{F}_5$ violates the octet rule.

The correct option is (A).