Question

Which of the following is/are true for $B_2$ and $C_2$ molecules according to M.O.T?

• A. Both are having 1 $\sigma$ and 1 $\pi$ bond
• B. Both are having same bond length
• C. Both are having different bond order
• D. $B_2$ is paramagnetic and $C_2$ is diamagnetic in nature

Answer 1

Answer: (C), (D)

Both are having different bond order
$B_2$ is paramagnetic and $C_2$ is diamagnetic in nature

$B_2$ has $1$ sigma bond only and $C_2$ has $1$ sigma and $1$ pi bond. Hence, option A is incorrect.
$B_2$ and $C_2$ have different bond orders. Hence, they have different bond lengths. Thus, the option B is incorrect.
The bond orders of $B_2$ and $C_2$ are $1$ and $2$ respectively.
Thus, the option C is correct.
$B_2$ has $2$ unpaired electrons and is paramagnetic in nature
whereas $C_2$ has all paired electrons and is diamagnetic in
nature. Thus, the option D is correct.