Dalton’s atomic  theory:-  In 1808 Dalton published a new system of chemical philosophy in which the following proposals are there:-

1. Matter consists of indivisible atoms.
2. All the atoms of a given element have identical proportion like size, shape, mass but atoms of different elements have different masses.
3. When atoms of different elements combine in a fixed ratio, then compounds are formed.
4. In a chemical reaction, neither atoms are created nor destroyed but reorganized.

Limitations of Dalton’s law:-

1. It could not explain Gay Lussac’s law of gaseous volumes.
2. It could not explain existence of isotopes and isobars.
3. It could not explain why atoms combine to form molecules and which kind of forces are present in atoms.