Number of anti bonding electrons in ${\mathrm{O}}_2$ molecule are

The atomic number of oxygen is 8. So, total number of electrons present in

Oxygen molecule is 16. According to M.O theory, electronic configuration of ${\mathrm{O}}_2$ is given as below.

$\mathrm{\sigma }1{\mathrm{s}}^2<{\mathrm{\sigma }}^{*}1{\mathrm{s}}^2<\mathrm{\sigma }2{\mathrm{s}}^2<{\mathrm{\sigma }}^{*}2{\mathrm{s}}^2<\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{Z}}<\mathrm{\pi }2{\mathrm{p}}_{\mathrm{z}}^2<\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2=\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2$

${\mathrm{\pi }}^{*}2{\mathrm{p}}_{\mathrm{x}}^1={\mathrm{\pi }}^{*}2{\mathrm{p}}_{\mathrm{y}}^1$

No. of anti bonding electrons in ${\mathrm{O}}_2$ molecule is 6.