The incorrect postulates of the Dalton's atomic theory are :
(A) Atoms of different elements differ in mass.
(B) Matter consists of divisible atoms.
(C) Compounds are formed when atoms of different element combine in a fixed ratio.
(D) All the atoms of given element have different properties including mass.
(E) Chemical reactions involve reorganisation of atoms.
Choose the correct answer from the options given below :

Solution

Chemistry ma’am · 2 steps

Recall Dalton's five postulates first, then find the two statements that have been twisted.

1. Dalton's actual postulates. Matter is made of indivisible atoms. All atoms of one element are identical, including in mass. Atoms of different elements differ in mass. Compounds form when atoms combine in a fixed ratio. A chemical reaction only rearranges atoms; it never creates or destroys them.

   Statement	What Dalton said	Matches?
   (A) different elements differ in mass	Same	correct postulate
   (B) divisible atoms	Atoms are indivisible	incorrect
   (C) fixed ratio in compounds	Same	correct postulate
   (D) atoms of one element have different properties	Atoms of one element are identical, mass included	incorrect
   (E) reactions reorganise atoms	Same	correct postulate

2. So. Only (B) and (D) misstate Dalton's theory, so the answer is (a).

The idea to keep. Dalton's atoms are indivisible, and all atoms of one element are identical. Statements that twist either of these are the usual incorrect ones in such questions.

Answer from the NTA final answer key. Solution by PrepWiser.