Question

How many periods are called short periods in the long form of the periodic table? Give their : (i) periodic numbers, (ii) number of elements in each period, (iii) name one element in each period.

Answer 1

The first three periods are called short period.

a. The periodic numbers are 1,2,3.

b. The first period has 2 elements
Second period has 8 elements
Third period has 8 elements

c. First period has H and He - one element name Hydrogen
Second period has Li to Ne - one element name - Lithium
Third period has Na to Ar - one element name - Sodium