# What is an example of an electron configurations practice problem?

Why is the bond order of ${O}_{2}^{-}$ smaller than the bond order of ${N}_{2}^{-}$?
Hint: Draw out the molecular orbital diagram, fill it in, and try writing a configuration for it. These do not have the same orbital ordering. The bond order of ${O}_{2}^{-}$ is actually 3/2. The bond order of ${N}_{2}^{-}$ is 7/2, as expected.
$\left(2 s {\sigma}_{g}\right) \left(2 s {\sigma}_{u}^{\cdot}\right) \left(2 {p}_{x , y} {\pi}_{u}\right) \left(2 {p}_{z} {\sigma}_{g}\right) \left(2 {p}_{x , y} {\pi}_{g}^{\cdot}\right) \left(2 {p}_{z} {\sigma}_{u}^{\cdot}\right)$