(a) Why physical properties and chemical properties of an element are periodic function of their atomic numbers?

(b) How does Modern Periodic Law justifies one position for isotopes?

Asked by Topperlearning User | 24th Jul, 2017, 04:17: PM

Expert Answer:

(a) Physical and chemical properties of elements are determined by their atomic numbers which is equal to the number of electrons. 

By using the number of electrons, we can find out the number of valence electrons and hence the physical and chemical properties. 

(b) According to Modern Periodic Law, elements are arranged in the Modern Periodic Table in the increasing order of their atomic numbers. Isotopes have the same atomic number and different atomic mass. So, though they have different atomic masses still they are given the same position in the Modern Periodic Table. 

Answered by  | 24th Jul, 2017, 06:17: PM