Question

Dmitri mendeleev contribution to the periodic table.

Answer 1

In 1871, a Russian Chemist, Dimitri Mendeleev, gave a useful scheme for classification of elements. He presented the first regular periodic table in which elements of similar chemical properties were arranged in eight vertical columns called groups. The horizontal rows of table were called periods. He arranged elements in ascending order of their  atomic masses and found that elements having similar chemical properties appeared at regular intervals. This observation was called Periodic Law.