Chapter 7, Problem 94QP

Interpretation Introduction

Interpretation:

The reason that the ionization energy of calcium is greater than that of potassium is to be explained.

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 a gaseous cation is called the ionization energy.

The ionization energy increases across the period as, across a period, electrons start getting added, which increases the effective nuclear charge on the last electron. Hence, a large amount of energy is required to remove the electron.

The ionization energy decreases down the group as 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.