Question

Fill in the blanks based on features of Mendeleev's periodic table:

The vertical columns are called -------- and there are --------- groups.

Answer 1

Mendeleev periodic table :

In Mendeleev, periodic table elements were arranged on the basis of increasing atomic mass. During Mendeleev, only 63 elements were known so after studying the properties of elements he arranged them into vertical columns called groups and horizontal rows are called periods.

During arrangement, there were seven periods and eight groups in Mendeleev's periodic table.

Hence, The vertical columns are called groups and there are eight groups.