Question

What are the main feature of Mendeleev's periodic table?

Answer 1

Main features of Mendeleev's Periodic Table:
(a) There are seven horizontal rows in the periodic table. They are called periods and are numbered from 1 to 7.
(b) In a given period, there is a regular gradation in the properties of elements from left to right.
(c) There are eight vertical columns in the periodic table. These are named as groups. They are numbered from I to VIII. Groups I to VII are subdivided into subgroups A and B.