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.

For diatomic molecules, the correct statement($s$) about the molecular orbitals formed by the overlap to two $2 p_z$ orbitals is(are)

$(A)$ $\sigma$ orbital has a total of two nodal planes.

$(B)$ $\sigma^*$ orbital has one node in the $x z$-plane containing the molecular axis.

$(C)$ $\pi$ orbital has one node in the plane which is perpendicular to the molecular axis and goes through the center of the molecule.

$(D)$ $\pi^*$ orbital has one node in the $x y$-plane containing the molecular axis.

Which of the following molecular orbitals has maximum number of nodal planes ?

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

The correct electron affinity order is $(EA = -\Delta H_{EG})$ 

Which of the following is paramagnetic ?