When ${\mathrm{N}}_2^{+}$  is formed from ${\mathrm{N}}_2$  the bond order

If one electron is removed from the bonding orbital of ${\mathrm{N}}_2$  molecule, then Nଶ+ ion is formed. As per M.O theory if the electrons are removed from  bonding  orbital then the bond order is decreased. Since the formula used to find bond order in a molecule or ion is as below:

Bond order =$\frac{1}{2}\times \left(N_b-{\mathrm{N}}_{\mathrm{a}}\right)$

From the above formula,  if ${\mathrm{N}}_{\mathrm{b}}<{\mathrm{N}}_{\mathrm{a}}$ then the bond order is decreased.