Which of the following is paramagnetic?

Step-by-step solution

Oxygen ( O ₂ ) contains 2 unpaired electron, hence it is paramagnetic aligned & O ₂= 1 s^2 ^* 1 s^2 2 s^2 ^* 2 s^2 2 p_x^2 & 2 p_y^2 2 p_z^2 ^* 2 p_y^1 ^* 2 p_z^1 aligned