- Home
- Standard 11
- Chemistry
4.Chemical Bonding and Molecular Structure
hard
Give electron configuration, bond order and magnetic property, energy diagram in $\mathrm{MO}$ for Helium $\left( {{\rm{H}}{{\rm{e}}_2}} \right)$ molecule.
Option A
Option B
Option C
Option D
Solution

He $(Z=2)$, So, Total electron in $\mathrm{He}_{2}=4$
Electron configuration in $\mathrm{MO} \mathrm{He}_{2}:\left(\sigma_{1 s}\right)^{2}\left(\sigma_{1 s}^{*}\right)^{2}$
All electron are paired in $\mathrm{He}_{2}$, so it is diamagnetic.
Bond order $=\frac{1}{2}\left(\mathrm{~N}_{\mathrm{b}}-\mathrm{N}_{\mathrm{a}}\right)=\frac{1}{2}(2-2)=0$
Bond order in $\mathrm{He}_{2}$ is zero. So it is unstable and does not exist.
$\mathrm{MO}$ energy diagram of $\mathrm{He}_{2}$ is as under.
Standard 11
Chemistry