Discovery of the nucleus of an atom was due to the experiment carried out by:

A.Bohr

B.Rutherford

C.Moseley

D.Thomson

The nucleus of an atom was discovered through the famous gold foil experiment, where alpha particles were bombarded on thin gold foil.

Complete step-by-step solution –

The correct answer is B. Rutherford.

• The discovery of the nucleus was made by Ernest Rutherford in 1911 through his gold foil experiment.
• In this experiment, a beam of alpha particles (positively charged) was directed at a very thin sheet of gold foil.
• Most of the particles passed straight through the foil, but some were deflected at small angles, and a few bounced back.
• This result showed that:
  1. Most of the space inside an atom is empty.
  2. The positive charge and mass of the atom are concentrated in a small region at the center, called the nucleus.
• This led Rutherford to propose the nuclear model of the atom, where electrons revolve around the dense, positively charged nucleus, similar to planets revolving around the sun.

Additional Information:

• J.J. Thomson had earlier proposed the “plum pudding model” of the atom, but it could not explain Rutherford’s results.
• Niels Bohr later improved Rutherford’s model by explaining that electrons revolve in fixed energy levels (orbits).
• Henry Moseley studied X-ray spectra to establish the concept of atomic number, but he did not discover the nucleus.

Rutherford’s gold foil experiment was a turning point in atomic physics as it gave the first clear evidence of the existence of the atomic nucleus.