Which of the following species is not paramagnetic?

Step-by-step solution

CO has no unpaired electron while other have (Apply M.O.T) E n e r g y l e v e l F o r m ⇒ CO : like N 2 ; σ 1 S 2 < σ * 1 S 2 < σ 2 S 2 < π * 2 S 2 < π 2 P x 2 = π 2 P y 2 < σ 2 P z 2 ( NO unpaired e − ) O 2 : σ 1 S 2 < σ * 1 S 2 < σ 2 S 2 < σ * 2 S 2 < σ 2 P z 2 < π 2 P x 2 = π 2 P y 2 < π * 2 P x 1 = σ * 2 P y 1 ( 2 − unpaired e − ) B 2 : σ 1 S 2 < σ * 1 S 2 < σ 2 S 2 < σ * 2 S 2 < π 2 P x 1 = π 2 P y 1 ( 2 − unpaired e − ) NO : σ 1 S 2 < σ * 1 S 2 < σ 2 S 2 < σ * 2 S 2 < π 2 P x 2 = π 2 P y 2 < σ 2 P z 2 < π *