Which of the following was a major flaw in J. J. Thomson's plum pudding model of the atom?

• A. It proposed that atoms were indivisible and indestructible.
• B. It suggested that electrons were located only in fixed orbits.
• C. It could not explain the results of Rutherford's gold foil experiment.
• D. It assumed that atoms contained only protons and no electrons.

Answer: (C)

Verified step by step guidance

1. Understand the context of J. J. Thomson's plum pudding model: it proposed that the atom is a sphere of positive charge with negatively charged electrons embedded within it, like 'plums' in a 'pudding'.
2. Recall the key experimental evidence that challenged this model, specifically Rutherford's gold foil experiment, which involved firing alpha particles at thin gold foil and observing their scattering patterns.
3. Analyze why the plum pudding model failed: it predicted that alpha particles would pass through the atom with minimal deflection due to the diffuse positive charge, but Rutherford observed some particles were deflected at large angles, indicating a concentrated positive nucleus.
4. Recognize that the major flaw in Thomson's model was its inability to explain these large-angle deflections and the existence of a small, dense, positively charged nucleus.
5. Conclude that the correct criticism is that the plum pudding model could not explain the results of Rutherford's gold foil experiment, which led to the development of the nuclear model of the atom.