Question

In Rutherford's experiment,
(I) gold foil was selected.
(II) fast moving $\alpha$-particles were made to fall on the foil.
(III) most of the $\alpha$-particles were deflected by the foil by small angles.
Which of the above given statements is/are true?

• A. Only I
• B. II & III
• C. I & II
• D. All are correct

Answer 1

The correct option is C I & II

In Rutherford’s experiment, he selected a gold foil because he wanted as thin a layer as possible. This gold foil was about $1000$ atoms thick. $\alpha$-particles were bombarded on the foil.

Since they have a mass of $4u$, the fast-moving $\alpha$-particles have a considerable amount of energy. Most of the fast-moving $\alpha$-particles passed straight through the gold foil as shown in the figure.

Very few $\alpha$-particles were deflected by the foil by small angles.

Hence, Statements I and II are correct and III is incorrect.

Option C is the answer.