Among the following species, the diamagnetic molecule is

Correct decreasing order of bond order of oxygen species in $I$ to $IV$

$(I)$   $Na_2O_2$

$(II)$  $O_2 [AsF_6]$

$(III)$  $CsO_2$

$(IV)$  $O_2$

According to molecular orbital theory, the paramagnetism of ${O_2}$ molecule is due to presence of

Which of the following species would be expected paramagnetic

According to molecular orbital theory, the number of unpaired electron(s) in $\mathrm{O}_{2}^{2-}$ is :

Choose correct order