Chapter 14, Problem 90CP

Use the $\text{MO}$ model to determine which of the following has the smallest ionization energy:

${\text{N}}_{\text{2}}$ , ${\text{O}}_{\text{2}}$ , ${\text{N}}_{\text{2}}{}^{2-}$ , ${\text{N}}_{\text{2}}{}^{-}$ , ${\text{O}}_{\text{2}}{}^{+}$ . Explain your answer.