Question

State Mendeleev's periodic law. How many periods and group are there in the long form of the periodic table?

Answer 1

• Mendeleev's periodic law states the physical and chemical properties of elements are a periodic function of their atomic masses.
• There are seven periods and eighteen groups in the long form of the periodic table.
• The vertical column of the periodic table is known as Group.
• The horizontal row of elements in a periodic table is known as Period.