Question

$B_2$ molecule is diamagnetic. The highest occupied molecular orbital is of $\sigma$ type.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

If both assertion and reason are false

Answer 2

The total number of electrons in $B _{2}=10$ $B _{2}=\sigma 1 s^{2} \sigma^{*} 1 s^{2} \sigma 2 s^{2} \sigma^{*} 2 s^{2} \pi 2 p_{y}^{1} \pi 2 p_{z}^{1}$ It has two unpaired electrons $\therefore$ It is paramagnetic and the highest occupied molecular orbital is of $\pi$ type. Thus, both assertion and reason are false.