If you could ask Rutherford one question about his work, what would it be? Class 9

If you could ask Rutherford one question about his work, what would it be? Class 9

Question 1.

If you could ask Rutherford one question about his work, what would it be? (Page 144) Class 9

Answer:

A thoughtful question could be: "If the nucleus is so small and yet contains all the positive charge and most of the mass of the atom, what force is responsible for holding the positively charged protons together inside the nucleus without them flying apart due to their mutual repulsion?" This question relates directly to the limitation of Rutherford's model and the concept of nuclear force, which is relevant to the chapter.

Question 2.

Assertion (A): Rutherford concluded that most of the mass of an atom is concentrated in a small region at the centre called the nucleus.

Reason (R): According to Thomson’s model, electrons are embedded in a uniformly distributed positive charge sphere. (Page 145) Class 9

Choose the correct statement:

(i) Both A and R are true, but R is not the correct explanation of A.

(ii) Both A and R are true, and R is the correct explanation of A.

(iii) A is true, but R is false.

(iv) A is false, but R is true.

Answer:

(iii) A is true, but R is false.

Explanation: The Assertion (A) is true - Rutherford did conclude from the gold foil experiment that most of the mass of an atom is concentrated in a small, dense region called the nucleus. This was one of his key conclusions. However, the Reason (R) is false - it describes Thomson’s model (where electrons are embedded in a uniformly distributed positive charge sphere), which is actually the opposite of what Rutherford proposed. Thomson's model was the model that Rutherford disproved. So the reason does not explain the assertion, and in fact describes the model that the assertion's evidence argues against.