Among N O 2 + , K O 2 and N a 2 O 2 and N a A l O 2 , the paramagnetism exist in-

Step-by-step solution

The electron distribution in O 2 − is : σ 1 s 2 σ 2 s * 2 σ 2 s 2 σ 2 s * 2 σ 2 p x 2 σ 2 p y 2 σ 2 p z 2 σ 2 p y * 2 σ 2 p z * 1 ∴ O 2 2 - is diamagnetic and O 2 - is paramagnetic. In A l O 2 - , oxide ions O 2 - are present and oxide ion is diamagnetic. N O 2 has one unpair electron hence paramagnetic but N O 2 + has no unpair electron therefore diamagnetic