Which of the following species exhibits the diamangetic behaviour ?

Options

A. ` O_2^(2-)`
B. ` O_2^+`
C. `O_2`
D. `NO`

Answer

A

Explanation

This species has `18e^(-)` which are filled in such a way that all moecular orbitals are fully filled, so diamagnetic.
`sigma1 s^2 sigma^(**) 1 s^2 , sigma 2s^2 , sigma^(**) 2 s^2 , sigma 2p_(z)^(2), pi2p_(x)^(2)=pi2p_(y)^(2), pi^(**) 2p_(x)^(2)=pi^(**)2p_(y)^(2)`