The total number of antibonding electrons in C₂ and B₂ molecules respectively

$$\begin{gathered} {\mathrm{C}}_2\left(12{\mathrm{e}}^{-}\right) = \mathrm{\sigma }1{\mathrm{s}}^2\mathrm{\sigma }*1{\mathrm{s}}^2\mathrm{\sigma }2{\mathrm{s}}^2\mathrm{\sigma }*2{\mathrm{s}}^2\left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\right) \\ {\mathrm{B}}_2(10 {\mathrm{e}}^{-}) = \mathrm{\sigma }1{\mathrm{s}}^2\mathrm{\sigma }*1{\mathrm{s}}^2\mathrm{\sigma }2{\mathrm{s}}^2\mathrm{\sigma }*2{\mathrm{s}}^2\left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^1=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^1\right) \\ * \mathrm{represents} \mathrm{antibonding} \mathrm{orbitals}. \end{gathered}$$