The correct option is (c).
Explanation
Ernest Rutherford’s alpha-particle scattering experiment involved bombarding a very thin gold foil with high-energy alpha particles. The observations from this experiment led to the rejection of Thomson’s "plum pudding" model and the proposal of the nuclear model of the atom.
Statement-wise Analysis
- Statement 1 is Incorrect. Most of the alpha particles passed through the gold foil undeflected. This observation led to the conclusion that most of the space inside the atom is empty. Only a very small fraction of particles suffered large deflections.
- Statement 2 is Correct. A small fraction of the alpha particles was deflected by small angles. This indicated that the positive charge of the atom is not spread throughout the atom (as Thomson suggested) but is concentrated in a small volume that repels the positively charged alpha particles.
- Statement 3 is Correct. A very small number of particles (approximately one in 12,000) rebounded, meaning they were deflected by nearly 180 degrees. This observation suggested that the entire positive charge and most of the mass of the atom are densely concentrated in a very small region called the nucleus.
Key Takeaway: Rutherford’s experiment established that the atom consists mostly of empty space, with a tiny, dense, positively charged nucleus at the center, causing large deflections for only a minute fraction of alpha particles.