(N/A) Dalton's atomic theory is based on the following postulates:
$1$. All matter is made of indivisible particles called atoms.
$2$. All atoms of a given element are identical in mass and properties. Atoms of different elements have different masses and properties.
$3$. Compounds are formed by the combination of two or more different kinds of atoms in a fixed ratio.
$4$. $A$ chemical reaction is a rearrangement of atoms. Atoms are neither created nor destroyed in a chemical reaction.
Dalton's theory explains the law of definite proportions and the law of multiple proportions. It suggests that the smallest constituents of an element are atoms,and since elements often exist as molecules,this theory serves as the foundation for the molecular theory of matter.