Question

Given below are two statements :
Statement I : Most of the mass of the atom and all its positive charge are concentrated in a tiny nucleus and the electrons revolve around it, is Rutherford’s model.
Statement II : An atom is a spherical cloud of positive charges with electrons embedded in it, is a special case of Rutherford’s model.
In the light of the above statements, choose the most appropriate from the options given below.

• A. Both statement I and statement II are false
• B. Statement I is false but statement II is true
• C. Statement I is true but statement II is false
• D. Both statement I and statement II are true

Answer 1

The Correct Option is C

To address this question, we must evaluate the provided statements against historical atomic models.

Statement I: "The majority of an atom's mass and its entire positive charge are concentrated in a minuscule nucleus, with electrons orbiting it. This is Rutherford’s model."

• This description correctly aligns with Rutherford's atomic model. This model posits that an atom comprises a small, dense nucleus containing most of the atom's mass and all its positive charge. Electrons are situated externally to the nucleus, orbiting it. This model was derived from the gold foil experiment, which demonstrated alpha particle deflection, indicating the existence of a central positive core.
• Consequently, statement I is true.

Statement II: "An atom is a spherical cloud of positive charges with electrons embedded within it, representing a specific instance of Rutherford’s model."

• This statement accurately depicts the Thomson model of the atom, popularly known as the "plum pudding model." In this model, the atom is conceptualized as a sphere of positive charge with negative electrons dispersed throughout, analogous to plums in a pudding.
• Rutherford's model, in contrast, represented a substantial deviation from this concept by introducing the notion of a central nucleus. Therefore, Rutherford's model cannot be considered a variation or a subdivision of Thomson's model.
• Consequently, statement II is false.

Based on the preceding analysis, the accurate conclusion is: Statement I is true, while statement II is false.