Rutherford Model — Prelims Questions

In Rutherford's alpha-particle scattering experiment, which of the following observations was the most significant in concluding that the atom has a tiny, dense, positively charged nucleus?

According to Rutherford's model, what provides the necessary centripetal force for electrons orbiting the nucleus?

If the kinetic energy of the alpha particles in Rutherford's experiment is increased, how would the scattering angle for a given impact parameter generally change?

Which of the following is a major limitation of Rutherford's model based on classical physics?

An alpha particle approaches a gold nucleus (Z=79) with a certain kinetic energy. If the alpha particle were replaced by a proton (Z=1) with the same kinetic energy, how would the minimum distance of approach (closest approach) to the nucleus change?

If the gold foil in Rutherford's experiment was replaced by a foil of a heavier element with a larger atomic number (Z), how would the number of alpha particles scattered at large angles change, assuming all other conditions remain the same?