Question

What is meant in the periodic table by :

(a) a group, and

(b) a period ?

Answer 1

Groups in Periodic Table:

The elements arranged from top to bottom, called Groups. There are 18 groups in Periodic Table.

Example: First group has H, Li, Na, K, Rb, Cs and Fr.

Periods in Periodic Table:

The elements arranged in the order left to right, called Periods. There are seven periods in Periodic Table.

Example: Second Period has Li, Be, B, C, N, O, F and Ne.