Chapter 2, Problem 2.91SP

Interpretation Introduction

Interpretation:

The reason for the decreases in atomic radii when we move from left to right in a period of the periodic table has to be given.

Concept introduction:

Atomic radius:

It is half of the distance between the nuclei of two same atoms when they are chemically bonded.

For example: Chlorine molecule

The distance between the two chlorine atoms is $\text{198}\text{pm}$.

$\begin{array}{l}\text{Atomic}\text{radius}\text{of}\text{Cl}\text{atom}\text{=}\frac{\text{d}}{\text{2}}\\ \text{=}\frac{\text{198}\text{pm}}{\text{2}}\text{=}\text{99}\text{pm}\text{.}\end{array}$