Question

Calculate the bond order of ${\mathrm{He}}_2$.

Answer 1

Step: 1 Formula for calculating the bond order

$\mathrm{Bond}\mathrm{Order}=\frac{\mathrm{B}.\mathrm{M}.\mathrm{O}-\mathrm{A}.\mathrm{B}.\mathrm{M}.\mathrm{O}}{2}$

Step: 2 Electronic configuration of Helium molecule

${\mathrm{He}}_2=\mathrm{\sigma }1{\mathrm{s}}^2,{\mathrm{\sigma }}^{*}1{\mathrm{s}}^2$

Step: 3 Bond order of Helium molecule

Bond order is defined as the number of chemical bonds formed between two atoms.

Mathematically it can be defined as the difference between the electrons present in the bonding molecular orbitals and the antibonding molecular orbitals.

There are 2 electrons in the bonding molecular orbital and 2 electrons in the antibonding molecular orbital making the resultant electrons to be zero.

$\mathrm{Bond}\mathrm{order}=\frac{2-2}{2}=0$

Therefore, the bond order of the Helium molecule is 0.

Final Answer:

The bond order of the Helium molecule is zero.