Chapter 3, Problem 3.3P

Interpretation Introduction

Interpretation:

The stability of a ${\text{H}}_{\text{2}}$ molecule when one of its electrons has been promoted from the $\text{σ MO}$ to the ${\text{σ}}^{*}\text{ MO}$ with light is to be compared with two separated hydrogen atoms.

Concept introduction:

When the atomic orbitals (AOs) of two atoms overlap, the produce two molecular orbitals (MOs). One of these is lower in energy than the individual AOs, and the other one is higher in energy by an almost equal amount.