Rutherford's experiment showed that some substances allowed alpha particles to pass through them frequently. he theorized this happened because the nuclei were

Rutherford's experiment showed that some substances allowed alpha particles to pass through them less frequently. he theorized this happened because the nuclei were smaller.

Explanation:

Ernest Rutherford was the physicist that created the Rutherford model which described the atom as a structure with a small and positively charged nucleus (where most of the mass is concentrated) and negative constituents called electrons that would revolve around the nucleus like the planets revolve around the Sun.

To develop his model, he experimented by making alpha particles (high-speed lightweight atoms) bombard very thin pieces of gold foil. After he observed that a few alpha particles bounced back, he hypothesized that an atom should be composed of a tiny dense nucleus that was surrounded by mostly empty space.