Chapter 7, Problem 90QP

Interpretation Introduction

Interpretation:

The given elements such as $\text{P}$ , $\text{O}$ , and $\text{Mg}$ are to be ranked in order of ionization energy.

Concept Introduction:

The minimum amount of energy required to remove the most loosely bound electron from an isolated gaseous atom so as to convert it into gaseous cation is called ionization energy.

Ionization energy increases across the period, as across the group electron starts getting added which increases the effective nuclear charge on the last electron. Hence, a large amount of energy is required to remove the electron.

Ionization energy decreases down the group, as down the group a new shell is getting added which increases the distance of the last electron from the nucleus. Hence, a low amount of energy is required to remove the electron.