Q. Assuming that Hund’s rule is violated, the bond order and magnetic nature of the diatomic molecule $B_{2}$ is
A) 1 and diamagnetic
B) 0 and diamagnetic
C) 1 and paramagnetic
D) 0 and paramagnetic
Explanation
(a)
$B_{2}$: Total electrons = 10
Configuration : $\sigma 1s^{2}\ _{\sigma}^{*}1s^{2}\sigma 2s^{2}\ _{\sigma}^{*}2s^{2}\pi 2p_{x}^{1} = \pi 2p_{y}^{1}$
If Hund’s rule is violated, then
$\sigma 1s^{2}\ _{\sigma}^{*}1s^{2}{\sigma 2s^{2}\ _{\sigma}^{*}}_{\ }2s^{2}\ \pi 2p_{x}^{2} = \pi 2p_{y}^{0}$
So, diamagnetic
Bond order = $\frac{6 - 4}{2} = 1$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.