Question

Which of the following statements about Rutherford’s model of atom are correct ?
(i) Consider the nucleus as positively charged.
(ii) Established that the a-particles are four times as heavy as a hydrogen atom.
(iii) Can be compared to the solar system.
(iv) Was in agreement with Thomson’s model.
A. (i) and (iii)
B. (ii) and (iii)
C. (i) and (iv)
D. Only (i)

Answer 1

In this question we have been given certain statements. We have to find the correct ones which correspond to Rutherford’s model of atom. Thus, to answer the given question, we shall discuss Rutherford's atomic model.

Complete answer:
In the year 1911, Ernest Rutherford carried out an experiment which confirmed that an atom is made of a massive region of positive charge. This positive charge is concentrated at the centre and electrons revolve around this positive charge.

In his experiment of gold foil, Rutherford bombarded the alpha particles on a very thin sheet of gold foil. Surrounding this foil, he placed a photosensitive screen that would light up as the alpha particles struck it.

From the results, he inferred that all the positive charge was concentrated at the centre of the nucleus. The experiment showed that the rest of the atom is empty space, except for electrons which revolve around the nucleus.In many ways, Rutherford’s model of atoms represented the solar system. Here, the positive charge is at the centre like the sun and electrons revolve around it like a planet.Thus, his model is also known as planetary model.

Therefore, option (A) is the correct answer.

Note: Rutherford was not in agreement with Thomson’s Plum pudding model of atom. Thompson stated that electrons were present inside a positively charged soup. Rutherford also predicted the existence of neutrons but was unable to confirm it through experiments.