Question

Why do we need to classify elements?

Answer 1

to study all the elements in a better and a simpler way

Answer 2

In order for more convenient results of oxidation and reduction and all other elementary chemical process it is important to classify elements. Classification is important because It can give us exact information on which are metallic elements,non metallic elements,semi metallic elements, inert gas , or alkalines .
Thus for convenient and exact results Classification is the must