Suppose you are given a chance to repeat the alpha-particle scattering experiment using a thin sheet of solid hydrogen in place of the gold foil. (Hydrogen is a solid at temperatures below 14 K.) What results do you expect?
In the alpha-particle scattering experiment using a thin sheet of solid hydrogen instead of gold foil, the results would be significantly different. The hydrogen nucleus has an atomic number Z = 1, compared to gold which has Z = 79. This means the positive charge on the hydrogen nucleus is much smaller.
The electrostatic force of repulsion between the alpha-particle and the hydrogen nucleus would be much weaker than with gold. Consequently, the alpha-particles would experience very small deflections, and large-angle scattering would be extremely rare.
Additionally, unlike the gold nucleus which is about 50 times heavier than the alpha-particle and remains stationary, the hydrogen nucleus (proton) is lighter than the alpha-particle. Therefore, the assumption that the nucleus remains stationary during scattering would not hold, as the hydrogen nucleus would recoil when struck by the alpha-particle.
Explanation
The question tests understanding of the factors affecting alpha-particle scattering. The key points from the context are: (1) Gold has Z=79, providing strong repulsion, while hydrogen has Z=1; (2) The gold nucleus is 50 times heavier than an alpha-particle, allowing the assumption of a stationary nucleus; (3) Hydrogen nucleus is lighter than an alpha-particle, so this assumption fails. Students should recognize that both the smaller charge and the mass ratio would dramatically reduce large-angle scattering events.