Question

Bond-order of $H{e}_2^{+}$ is _____ but it is paramagnetic due to _____

• A. $0.5$, one unpaired electron
• B. $1$, two unpaired electron
• C. $0.5$, no unpaired electron
• D. $1$, one unpaired electron

Answer 1

The correct option is A $0.5$, one unpaired electron

Species $H{e}_2^{+}$ has $3$ electrons.

MO Electronic Configuration is = $\sigma 1s^2{\sigma }^{\ast }1s^1$,

Bonding electrons = $2$ and antibonding electrons = $1$

Bondorder=$\frac{2-1}{2}=\frac{1}{2}$

Since an unpaired electron is present. So, it is paramagnetic.

So, the correct option is $A$