Which of the following is paramagnetic ?
$N{O^ + }$
$CO$
$O_2^{2 - }$
$B_2$
Which of the following is not paramagnetic
In the synergic bond of metal carbonyls
According to molecular theory, the species among the following that does not exist is
The species having bond order different from that in $\mathrm{CO}$ is
During change of $O_2$ to $O_2^-$ ion, the electron adds on which one of the following orbitals