Question

Which of the following statements about Rutherford’s model of the atom are correct?

(i) considered the nucleus as positively charged

(ii) established that the $\mathrm{\alpha }$–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

The correct option is A

(i) and (iii)

Explanation for correct option:

A. (i) and (iii)

Postulates of Rutherford's model of an atom:

• In his experiment, the $\mathrm{\alpha }$-particles were made to come down on a thin gold foil.
• Many of the $\mathrm{\alpha }$-particles passed linearly through the gold foil.
• Some of the particles deviated at small angles.
• One out of every $12000$ particles appeared to bounce.

Conclusion of Rutherford's model of an atom:

• The space inside an atom is empty as most of the $\mathrm{\alpha }$-particles passed without deflection through the gold foil.
• The positive charge occupies a minimum space which indicates that very few particles were diverted from their path.
• A very small proportion of α-particles were diverted by ${180}^{\mathrm{o}}$.
• He considered the nucleus as positively charged.
• It can be compared to the solar system.

Explanation for incorrect options:

The conclusions of the Rutherford model are discussed above. Thus, his model was not in the agreement with Thomson’s model. Thus options B, C, and D are incorrect.

Hence the correct option is A i.e. (i) and (iii).