Question

Which postulate of Dalton's atomic theory can explain the law of definite proportions?​

Answer 1

Answer :-

Law of definite proportion states that the elements are always present in definite proportions by mass.

The last postulate of Dalton's atomic theory which states that, "In a given compound, the relative number and types of atoms are constant." can explain the law of definite proportion.

Answer 2

First of all, don't call them postulates. Scientists don't propose postulates; mathematicians do.

Second, he didn't. Not really anyway.

All he did was propose the five points of his theory to explain the laws of conservation of mass, definite proportions, and multiple proportions.

The previously proposed theory of atoms (from way back; the existence of atoms had been discussed for a long time) handily explained these three laws, and he came up with his laws to consolidate the idea.