Chemistry - CHEMICAL BONDING Question with Solution | TestHub

The molecular orbitals filled with electrons according Afbaue, Pauli's exclusion and Hund's rules.

$\left({\mathrm{\sigma }}_{1\mathrm{s}})<\right({{\mathrm{\sigma }}^{*}}_{1\mathrm{s}})< ({\mathrm{\sigma }}_{2\mathrm{s}})< ({\mathrm{\sigma }}_{2\mathrm{s}}*)<\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{x}}})=\right({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}})<\left({\mathrm{\sigma }}_{2{\mathrm{p}}_{\mathrm{z}}}\right)<\left({{\mathrm{\pi }}^{*}}_{2{\mathrm{p}}_{\mathrm{x}}})=\right({{\mathrm{\pi }}^{*}}_{2{\mathrm{p}}_{\mathrm{y}}})<\left({{\mathrm{\sigma }}^{*}}_{2{\mathrm{p}}_{\mathrm{z}}}\right)$

The important characteristic feature of this order is that the energy of ${\mathrm{\sigma }}_{2\mathrm{pz}}$ molecular orbital is higher than that of ${\mathrm{\pi }}_{2\mathrm{px}} \mathrm{and} {\mathrm{\pi }}_{2\mathrm{py}}$ molecular orbitals, it is due to 2s-2p mixing is allowed in case of nitrogen molecule.