Odd number electron generally indicates paramagnetic nature and even number of electron  diamagnetic nature

${\text{O}}_2^{2-}\Rightarrow 18$Electron diamagnetic.

${\text{O}}_3\Rightarrow 24$Electron diamagnetic.

${\text{N}}_2\text{O} \Rightarrow 22$Electron diamagnetic.




${\text{O}}_2^{-}\Rightarrow 17$Electrons one unpaired electron paramagnetic.