The decreasing order of stability of ${\mathrm{O}}_2,{\mathrm{O}}_2^{-},{\mathrm{O}}_2^{+}$ $\mathrm{and}$ ${\mathrm{O}}_2^{2-}$is: 

1. ${\mathrm{O}}_2^{+}>{\mathrm{O}}_2>{\mathrm{O}}_2^{-}>{\mathrm{O}}_2^{2-}$

2. ${\mathrm{O}}_2^{2-}>{\mathrm{O}}_2^{-}>{\mathrm{O}}_2>{\mathrm{O}}_2^{+}$

3. ${\mathrm{O}}_2>{\mathrm{O}}_2^{+}>{\mathrm{O}}_2^{2-}>{\mathrm{O}}_2^{-}$

4. ${\mathrm{O}}_2^{-}>{\mathrm{O}}_2^{2-}>{\mathrm{O}}_2^{+}>{\mathrm{O}}_2$

A pair in which both species are not likely to exist is:

Combination of atoms A and B that forms an anti-bonding molecular orbital is :

1. $\frac{{\mathrm{\Psi }}_{\mathrm{A}}^2}{{\mathrm{\Psi }}_{\mathrm{B}}^2}$

2. ${\mathrm{\Psi }}_{\mathrm{A}}^2\times {\mathrm{\Psi }}_{\mathrm{B}}^2$

3. ${\mathrm{\Psi }}_{\mathrm{A}}+{\mathrm{\Psi }}_{\mathrm{B}}$

4. ${\mathrm{\Psi }}_{\mathrm{A}}-{\mathrm{\Psi }}_{\mathrm{B}}$

From the perspective of molecular orbital theory, which statement is false?