Give an account of the process adopted by Mendeleev for the classification of elements. How did he arrive at ''periodic law'' ?

Explanation

The basis of classification of elements adopted was atomic masses of the elements. The elements were arranged in order of increasing atomic masses.
Elements with similar properties were kept in a particular grwoup in order of increasing aromic masses.
Elements placed in a particular group (or sub group) were having same valency.
Note : Please note that when Mendeleev arranged the elements in the Periodic Tabel only 63 elements were known. Even noble gas or inert gas elements were adjust at a later stage. Moreover, many groups were left in the table.