Which of these models resembles the solar system in which the nucleus plays the role of sun and the electrons that of revolving planets?

The correct answer is Rutherford’s Nuclear Model of Atom.

Key Points

• Rutherford’s Nuclear Model was proposed by Ernest Rutherford in 1911 after his famous gold foil experiment.
• The model describes the atom as consisting of a dense, positively charged nucleus at the center, surrounded by electrons that revolve in circular paths.
• It resembles a miniature solar system where the nucleus acts like the sun and electrons behave like planets revolving around the sun.
• Most of the atom’s mass is concentrated in the nucleus, while the electrons occupy the surrounding space.
• Rutherford’s model successfully explained the scattering of alpha particles observed in his experiment, disproving the earlier “plum pudding model” proposed by J.J. Thomson.

Additional Information

• Gold Foil Experiment:
  • Rutherford directed alpha particles at a thin sheet of gold foil to study atomic structure.
  • Most alpha particles passed straight through, but some were deflected at large angles, indicating the presence of a dense nucleus.
• Limitations of Rutherford’s Model:
  • It could not explain the stability of electrons in circular orbits due to electromagnetic radiation loss.
  • Later, Bohr’s model addressed this limitation by introducing quantized energy levels.
• Thomson’s Plum Pudding Model:
  • Proposed by J.J. Thomson, it described the atom as a sphere of positive charge with electrons embedded like raisins in a pudding.
  • This model was disproven by Rutherford’s experiment.
• Comparison with Bohr’s Model:
  • Bohr’s model refined Rutherford’s by proposing quantized orbits for electrons to explain atomic stability and spectral lines.
  • Bohr incorporated Planck’s quantum theory into atomic structure.