Among the following species$N _{2}, N _{2}^{+}, N _{2}^{-}, N _{2}{ }^{2-}, O _{2}, O _{2}{ }^{+}, O _{2}^{-}, O _{2}{ }^{2-}$ the number of species showing diamagnetism is.

Bond order normally gives idea of stability of a molecular species. All the molecules viz. $H_2,\,\, Li_2$ and $B_2$ have the same bond order yet they are not equally stable. Their stability order is

Maximum unpaired electrons are present in

Which of the following is paramagnetic ?

The bond order in $NO$ is $2.5$ while that in $N{O^ + }$ is $3.$ Which of the following statements is true for these two species