Differentiate between:

Periods and groups.

The periodic table is a tabular arrangement of the elements in vertical columns and horizontal rows indicating the regular trend in the properties of an element.

The horizontal rows are called periods while vertical columns are known as groups.

S.No	Period	Group
1	The horizontal rows in the periodic table are called periods	The vertical columns in periodic table are known as groups.
2	There are seven periods in the periodic table.	There are 18 groups in the periodic table.
3	Moving down the group the shell increases. (n=1,2,3,4…)	The no. of shell remain the same in a particular period
4	The properties of the members of the same group are similar	The properties vary from left to right in periods.
5	the members of same group have the same valency	The valency varies from one end to another