Question

b) Explain the Mendeleev's periodic law and modern
periodic law. Give any two defect of Mendeleev's
periodic table.​

Answer 1

Answer:

According to Mendeleev's Periodic Law, isotopes of an element must be given separate places in the periodic table because they have different atomic masses. It does not explain the electronic arrangement of elements. Elements that are chemically similar such as Gold and Platinum have been placed in separate groups.

Answer 2

Answer:

Mendeleev periodic Law states that the physical and chemical properties of the elements are a periodic function of their atomic weights while Modern periodic law states that physical and chemical properties of elements are a periodic function of their numbers. Thus, the basic difference in apporoach between Mendeleev's periodic Law and Modern periodic Law is the change in basis of classification of element from atomic weight to atomic number.