Chapter 3, Problem 3.4P

Interpretation Introduction

Interpretation:

An energy diagram of ${\text{H}}_{\text{2}}^{\text{+}}$ ion, similar to Figure 3-7, is to be drawn. The stability of this ion relative to an isolated atom and a ${\text{H}}^{+}$ ion is to be determined.

Concept introduction:

The stability of a molecule or an ion relative to the separated atoms depends on the number of electrons in its bonding and antibonding MOs. More the number of electrons in the bonding MO, more the stability. On the other hand, presence of electron(s) in the antibonding orbital destabilizes the molecule (or ion).

Completely removing an atom’s electron to ionize it requires supplying energy to the electron. The amount of energy needed for this is higher than that needed for promoting an electron to a higher energy orbital of the molecule or atom.