Which hypothesis was supported by the results of the Rutherford gold foil experiment and led to the discovery of the proton?

• A. Electrons are distributed evenly throughout the atom.
• B. Atoms contain a small, dense, positively charged nucleus.
• C. All atomic mass is concentrated in the electron cloud.
• D. Atoms are indivisible and cannot be broken down further.

Answer: (B)

Verified step by step guidance

1. Understand the context of the Rutherford gold foil experiment: it involved firing alpha particles at a thin sheet of gold foil to observe how they scattered.
2. Recall the key observation: most alpha particles passed straight through the foil, but some were deflected at large angles, and a few even bounced back.
3. Analyze what these observations imply about atomic structure: if atoms were uniform and diffuse, alpha particles would pass through with minimal deflection; large deflections suggest a concentrated positive charge.
4. Formulate the hypothesis supported by these results: atoms contain a small, dense, positively charged nucleus that causes the deflection of alpha particles.
5. Connect this hypothesis to the discovery of the proton: the positively charged nucleus was later understood to contain protons, fundamental particles with positive charge.