Addition of an electron to an antibonding molecular orbital:

Stability of the species $Li_2$,$Li_2^-$ and $Li_2^+$ increases in the order of $:-$

Based on the Molecular Orbital Theory,what is the number of non-bonding electron pairs in $O_2^{2-}$?

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:

The molecular orbital configuration of a diatomic molecule is
$\sigma 1s^2 \sigma^* 1s^2 \sigma 2s^2 \sigma^* 2s^2 \sigma 2p_x^2 \pi 2p_y^2 \pi 2p_z^2$
Its bond order is

Which of the following statements are correct for the peroxide ion $(O_{2}^{2-})$?
$(i)$ It has a bond order of $1$.
$(ii)$ It is diamagnetic.
$(iii)$ It has four completely filled antibonding molecular orbitals.
$(iv)$ It is isoelectronic with neon.