Chemistry - CHEMICAL BONDING Question with Solution | TestHub

For B₂ (10 electrons), the configuration is $(\sigma 1s{)}^2({\sigma }^{\ast }1s{)}^2(\sigma 2s{)}^2({\sigma }^{\ast }2s{)}^2(\pi 2p_x{)}^1(\pi 2p_y{)}^1$. Symmetrical orbitals are $\sigma 1s$, ${\sigma }^{\ast }1s$, $\sigma 2s$, ${\sigma }^{\ast }2s$, containing 8 electrons.

For F₂ (18 electrons), the configuration is $(\sigma 1s{)}^2({\sigma }^{\ast }1s{)}^2(\sigma 2s{)}^2({\sigma }^{\ast }2s{)}^2(\sigma 2p_z{)}^2(\pi 2p_x{)}^2(\pi 2p_y{)}^2({\pi }^{\ast }2p_x{)}^2({\pi }^{\ast }2p_y{)}^2$. Symmetrical orbitals are $\sigma 1s$, ${\sigma }^{\ast }1s$, $\sigma 2s$, ${\sigma }^{\ast }2s$, $\sigma 2p_z$, containing 10 electrons.

Total symmetrical electrons = $8+10=18$.