Question

describe periods and gruops of long from of periodic table ?​

Answer 1

Explanation:

A period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left. ... A group is a vertical column of the periodic table, based on the organization of the outer shell electrons. There are a total of 18 groups.

Modern periodic table (i.e. long form of table) is based on the periodic law which says that physical and chemical properties of the elements are periodic function of their atomic numbers.