Question

The Rutherford $\alpha$-particle experiment shows the most of the $\alpha$-particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom?

• A. Atom is hollow.
• B. The whole mass of the atom is concentrated in a small centre called nucleus
• C. Nucleus is positively charged
• D. All the above

Answer 1

The correct option is D All the above

Rutherford concluded from the $\alpha$-particle scattering experiment that
(i) Most of the space inside the atom is empty because most of the -particles passed through the gold foil without getting deflected.
(ii) Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
(iii) A very small fraction of $\alpha$-particles were deflected by 1800, indicating that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.
From the data, he also calculated that the radius of the nucleus is about 105 times less than the radius of the atom.
On the basis of his experiment, Rutherford put forward the nuclear model of an atom, which had the following features:
(i) There is a positively charged centre in an atom called the nucleus. Nearly all the mass of an atom resides in the nucleus.
(ii) The electrons revolve around the nucleus in circular paths.
(iii) The size of the nucleus is very small as compared to the size of the atom