Chapter 4, Problem 119CP

Interpretation Introduction

Interpretation: The existence of the ${\text{He}}_{\text{2}}$ molecule and its dissociation, on basis of the molecular orbital theory is to be explained.

Concept introduction: The electronic configuration for multi-electron diatomic molecule is written using the molecular orbitals, derived from the ${\text{H}}_{\text{2}}^{\text{+}}$ molecular ion.

The bond order is calculated by difference between the anti-bonding electrons and the bonding electrons by two. This can be stated as,

$\text{Bond}\text{order}=\frac{\left[\left(\begin{array}{l}\text{Electrons}\text{in}\\ \text{bonding}\text{orbitals}\end{array}\right)-\left(\begin{array}{l}\text{Electrons}\text{in}\\ \text{anti-bonding}\text{orbitals}\end{array}\right)\right]}{2}$

As the bond order increases, the stability also increases. The bond order is directly proportional to the bond energy and inversely proportional to the bond length.

To determine: The explanation regarding the existence and the dissociation of the ${\text{He}}_{\text{2}}$ molecule.