Chapter 4.4, Problem 3PPB

Interpretation Introduction

Interpretation: From the given pairs, the pair whose atomic size cannot be compared using the periodic table should be determined.

Concept Introduction:

Periodic Table: The available chemical elements are arranged considering their atomic number, the electronic configuration and their properties. The elements placed on the left of the table are metals and non-metals are placed on right side of the table.

In periodic table the horizontal rows are called periods and the vertical column are called group.

There are seven periods and 18 groups present in the table and some of those groups are given special name as follows,

$\begin{array}{l}\text{Group-1}\to \text{Alkali metal}\\ \text{Group-2}\to \text{Alkaline metals}\\ \text{Group-16}\to \text{Chalcogens}\\ \text{Group-17}\to \text{Halogens}\\ \text{Group-18}\to \text{Noble gases}\end{array}$

Atomic Number: Atomic number of the element is equal to the number of protons present in the nucleus of the element which is denoted by symbol Z. The superscript presents on the left side of the symbol of the element.

Atomic radius: Atomic radius is the distance between the atomic nucleus and outermost electron of an atom. From the atomic radius, the size of atoms can be visualized. But there is no specific distance from nucleus to electron due to electron cloud around the atom does not have well-defined boundary.

The atomic radius follows the specific trend in the periodic table that it gets decreases as we go from left to right of the period due to increased nuclear charge the electrons gets added to the same sub-shell strongly binds resulting to decrease in the size.

It increases as we move from top to bottom of the table due to addition of shell in the element.

To determine: The pair whose atomic size of the elements cannot be compared using the table.