$He_{2}$ molecule is not possible. Explain.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) $He$ $(Z=2)$,so the total number of electrons in $He_{2}$ is $4$.
The molecular orbital $(MO)$ electronic configuration of $He_{2}$ is: $(\sigma_{1s})^{2} (\sigma_{1s}^{*})^{2}$.
All electrons are paired in $He_{2}$,so it is diamagnetic.
Bond order $= \frac{1}{2} (N_{b} - N_{a}) = \frac{1}{2} (2 - 2) = 0$.
Since the bond order of $He_{2}$ is $0$,the molecule is unstable and does not exist.
The $MO$ energy diagram of $He_{2}$ is shown below.

Explore More

Similar Questions

Among the following,the species having the smallest bond length is:

The number of nodal planes present in $\sigma^{*}s$ antibonding orbitals is

When $\psi_A$ and $\psi_B$ are the wave functions of atomic orbitals,then $\sigma^*$ is represented by :

Identify all the species that do not exist: $H_2^{+}, He_2^{2+}, Li_2^{2-}, Ne_2, Be_2^{-}, He_2$.

In which of the following transformations,the bond order has increased and the magnetic behaviour has changed?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo