The molecules with unpaired electrons are paramagnetic and molecules with all electrons paired are diamagnetic. In general molecules with an even number of electrons (except 10 and 16 electrons) are diamagnetic
N214e−diamagnetic
N2+13e−paramagnetic
N2−15e−paramagnetic
N22−16e−paramagnetic
O216e−paramagnetic
O2+15e−paramagnetic
O2−17e−paramagnetic
O22−18e−diamagnetic