The bond length of the species O2, O2+ and O2- are in the order of

A
$O_{2}^{+} > O_{2} > O_{2}^{-}$
B
$O_{2}^{+} > O_{2}^{-} > O_{2}$
C
$O_{2} > O_{2}^{+} > O_{2}^{-}$
D
$O_{2}^{-} > O_{2} > O_{2}^{+}$

Solution:

As bond order increases bond length decrease, the bond order of species are

$= \frac{Number of bonding electron - Number of antibonding electron}{2} For O_{2} = \frac{10 - 6}{2} = 2; O_{2}^{+} = \frac{10 - 5}{2} = 2.5 O_{2}^{-} = \frac{10 - 7}{2} = 1.5 So, bond order O_{2}^{+} > O_{2} > O_{2}^{-} and bond length are O_{2}^{+} > O_{2} > O_{2}^{-} .$