Question

Which of the following species have maximum number of unpaired electron?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

To know the number of unpaired electrons, we have to draw to draw the MO energy level diagram of following species and then fill the electros keeping in mind all the rules.

In $O_2\to 2$ unpaired~electrons
$\to 1$ unpaired electron

$O_2^{-}\to 1$ unpaired electron

$O_2^{2-}\to 0$ unpaired electron

So, $O_2$ has maximum number of unpaired electrons.