Question

Explain the need or significance of periodic classification of elements?

Answer 1

The neat arrangement is always necessary when we have a bundle of items. we can relate the elements classification as with stationary stuff. We have $118$ elements and this amount becomes more when these elements combine with each other and form compounds. Every element has some significance property which cannot be just ignored so a neat classification is necessary.

Complete step-by-step answer:
If we have seen the periodic table which was arranged on the basis of atomic mass by scientist Mendeleev it was a neat classification of all elements which were discovered at that time on the basis of their masses so a good relation gets set up. Now the periodic table that we generally study is made by Henry Mosely and it was done on the basis of atomic number. There are groups and periods where elements are arranged such that each group have some set of elements which are similar in properties like group $1$ we have $H,\,Li,\,Na,\,K,\,Rb,\,Cs,\,Fr$ these elements have same number of electrons in outermost shell hence they are put together.

We have different groups having sets of elements and periods. There are some trends which are seen when we move either from left to right or down the group. Like electronegativity which increases while moving left to right, it decreases as we move down the group. So the elements are arranged for learning them, for understanding them and their properties well.

Note: In the beginning there are only $38$ elements present so they will get arranged on the basis of periodic mass by Sir Mendeleev but as the discovery of other elements evolves the need for better classification comes. The Periodic table of Henry Mosely is a better classification because of the generalized periods and groups. Also blocks electronic configuration, classification of metals and nonmetals etc.