What was Dalton's atomic theory, and which of its postulates have since been proven incorrect?

Dalton's atomic theory stated that: 

1. All matter is composed of indivisible atoms. 

2. Atoms of a given element are identical in mass and properties. 

3. Compounds are formed by a combination of two or more different kinds of atoms. 

4. A chemical reaction is a rearrangement of atoms. 

The postulates proven incorrect are: 

1. Atoms are indivisible (they can be divided into subatomic particles). 2. Atoms of a given element are identical in mass (isotopes exist, which have different masses).