Choose the correct option from the following options given below :

Explanation:

To answer this question, let's analyze each statement based on Rutherford's and Thomson's atomic models.

1. (a)In the ground state of Rutherford's model, electrons are in stable equilibrium. While in Thomson's model, electrons always experience a net force.
   • Rutherford's model: Electrons revolve around the nucleus in orbits due to centripetal force. They are not in stable equilibrium because this motion involves constant acceleration.
   • Thomson's model: Electrons are embedded in a positively charged sphere. They experience forces but are considered to be balanced within the sphere.
   • Conclusion: This statement is incorrect because electrons are not in stable equilibrium in Rutherford's model.
2. (b)An atom has a nearly continuous mass distribution in Rutherford's model but has a highly non-uniform mass distribution in Thomson's model.
   • Rutherford's model: Most of the atom's mass is concentrated in the nucleus, with electrons revolving around it. The mass distribution is highly non-uniform.
   • Thomson's model: Mass is distributed almost uniformly across the positive sphere, with electrons embedded in it.
   • Conclusion: This statement is incorrect because Rutherford's model has non-uniform mass distribution, while Thomson's model has a nearly uniform mass distribution.
3. (c)A classical atom based on Rutherford's model is doomed to collapse.
   • Rutherford's model: According to classical physics, electrons in orbit would radiate energy and spiral into the nucleus, causing the atom to collapse.
   • Conclusion: This statement is correct, as classical physics predicts the atom's instability.
4. (d)The positively charged part of the atom possesses most of the mass in Rutherford's model but not in Thomson's model.
   • Rutherford's model: The nucleus, which is positively charged, contains most of the atom's mass.
   • Thomson's model: Mass is spread out more uniformly and not concentrated in any specific part.
   • Conclusion: This statement is correct because the nucleus in Rutherford's model holds most of the atom's mass, unlike Thomson's model.

Answer:

The correct option is: (c) A classical atom based on Rutherford's model is doomed to collapse.