Chapter 6, Problem 70A

Interpretation Introduction

Interpretation:

It is to be explained why the first ionization enthalpy of non-metals is higher than that of alkali metals.

Concept Introduction : The first ionization energy is the energy needed for the extraction of the outermost electron from the neutral gaseous atom.

Answer to Problem 70A

Nonmetals are smaller in size than alkali metals.

Explanation of Solution

The ionization energy is inversely related to atomic size. Alkali metals are placed on the extreme left, and the nonmetals are placed on the right side of the periodic table. The atomic size decreases across the period. So outermost electrons are held tightly by the nucleus and hence, more energy is required for the removal of outermost electrons.

Thus, the first ionization energy of non-metals is much higher than that of alkali metals.