What was Dalton's atomic theory, and which of its postulates have since been proven incorrect?
ChemistryClass 9CBSEAnswered 12 May 2026
Answer
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).
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