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 :

The correct option is (B), (D) only.

Dalton's atomic theory, proposed by John Dalton in 1808, consists of several postulates that describe the nature of matter and atoms. Let us analyze each of the statements given in the question to determine whether they are correct or incorrect according to Dalton's atomic theory:

(A) Atoms of different elements differ in mass:
According to Dalton's theory, atoms of different elements have different masses and chemical properties. Therefore, this is a correct postulate of Dalton's atomic theory.

(B) Matter consists of divisible atoms:
Dalton's theory states that matter consists of indivisible atoms (atoms cannot be created, destroyed, or divided into smaller parts). Therefore, the claim that matter consists of divisible atoms is an incorrect postulate.

(C) Compounds are formed when atoms of different elements combine in a fixed ratio:
According to Dalton's theory, atoms of different elements combine in simple, fixed numerical ratios to form chemical compounds. Therefore, this is a correct postulate of Dalton's atomic theory.

(D) All the atoms of a given element have different properties including mass:
Dalton's theory states that all atoms of a given element are identical in all respects, including their mass and chemical properties. Therefore, the statement that they have different properties including mass is an incorrect postulate.

(E) Chemical reactions involve reorganisation of atoms:
Dalton's theory states that chemical reactions involve only the separation, combination, or rearrangement of atoms; atoms themselves are neither created nor destroyed in a chemical reaction. Therefore, this is a correct postulate of Dalton's atomic theory.

Based on the analysis above, the incorrect postulates of Dalton's atomic theory are statements (B) and (D).