Chapter 2, Problem 2.81CP

Interpretation Introduction

Interpretation:

The reason should be explained for the hydrogen is placed in 1A group even is not an alkali, sometimes placed in 7A even not a halogen.

Concept introduction:

Alkali metals:

Alkali metals are given below,

Lithium ($\text{Li}$), sodium ($\text{Na}$), potassium ($\text{K}$), rubidium ($\text{Rb}$), cesium ($\text{Cs}$), and francium ($\text{Fr}$).

Halogens:

Halogens are given below,

Fluorine ($\text{F}$), chlorine ($\text{Cl}$), bromine ($\text{Br}$), iodine ($\text{I}$), and astatine ($\text{At}$).