Give two drawbacks of Dalton's atomic theory of matter.

Dalton's atomic theory:

1. John Dalton, a famous chemist and physicist of 1808, gave a scientific theory on the nature of matter.
2. The theory says that every substance is made up of tiny particles called atoms, and they are indivisible.

Drawbacks of Dalton's atomic theory:

1. The theory fails to explain how atoms combine with different elements to form a group.
2. Dalton fails to explain isotopes as isotopes have different masses. He claims that all the atoms have identical masses and densities.