Question

In the Thomson's model of atom, which of the following statements are correct?

(i) The mass of the atom is assumed to be uniformly distributed over the atom.

(ii) The positive charge is assumed to be uniformly distributed over the atom.

(iii) The electrons are uniformly distributed in the positively charged sphere.

(iv) The electrons attract each other to stabilize the atom.

• A. (i), (ii) and (iii)
• B. (i) and (iii)
• C. (i) and (iv)
• D. (ii), (iii) and (iv)

Answer 1

The correct option is A

(i), (ii) and (iii)

Explanation for the correct option:

Option (A): (i), (ii) and (iii):

1. Thomson was the first to propose a detailed model of an atom.
2. He proposed that an atom consists of a uniform sphere of positive charge in which the negatively charged electrons are embedded uniformly.
3. He assumed that the mass of the atom was uniformly distributed over the atom.
4. He concluded that the total positive and negative charges are equal in magnitude so the atom is electrically neutral.
5. The mass of an atom, positive charge and electrons are uniformly distributed according to Thomson.
6. Thus, statements (i), (ii) and (iii) are correct.

Explanation for the incorrect options:

Option (B): (i) and (iii):

This option is incorrect as it does not explain that the positive charge is assumed to be uniformly distributed over the atom.

Option (C): (i) and (iv):

Thomson's model of an atom did not explain that the electrons attract each other to stabilize the atom.

Option (D): (ii), (iii) and (iv):

Thomson's model of an atom did not explain that the electrons attract each other to stabilize the atom.

Thus, Option (A) is the correct option.