Introduction

• It is always easy to distinguish the items from one another by sorting them on some basis.
• In malls or in shops we always get the things sorted at their respective places.

Need for the arrangement of elements in an organised manner

Robert Boyle (1661) defined an element as any substance that cannot be decomposed into a further simple substance by a physical or chemical change

It  was Difficult to keep in memory the characteristics of individual elements and their compounds,this lead to to the classification of elements