Which one did Rutherford consider to be supported by the results of experiments in which a-particles were scattered by gold foil?

Options

A. The nucleus of an atom is held together by forces which are much stronger than electrical or gravitational forces
B. The force of repulsion between an atomic nucleus and an a-particle varies with distance according to inverse square law
C. a particles are nuclei of Helium atoms
D. Atoms can exist with a series of discrete energy levels

Explanation

To solve the question "Which one did Rutherford consider to be supported by the results of experiments in which alpha particles were scattered by gold foil?", we will analyze the options provided and determine which one aligns with Rutherford's conclusions from his experiments.

### Step-by-Step Solution:

1. **Understand the Experiment**: Rutherford conducted the gold foil experiment where alpha particles were directed at a thin foil of gold. The scattering of these particles provided insights into the structure of the atom.

2. **Analyze the Options**:
- **Option A**: "The nucleus of an atom is held together by forces which are much stronger than electrical or gravitational forces."
- This statement is true in the context of nuclear forces, but Rutherford's experiment did not provide evidence for this. He did not explore the nature of the forces holding the nucleus together.

- **Option B**: "The force of repulsion between an atomic nucleus and an alpha particle varies with distance according to inverse square law."
- This statement is consistent with Rutherford's findings. He observed that the alpha particles were repelled by a dense central nucleus, and the scattering angles were related to the distance from the nucleus, which supports the inverse square law of electrostatic force.

- **Option C**: "Alpha particles are nuclei of helium atoms."
- While this statement is true, it was already known prior to Rutherford's experiment and does not represent a conclusion drawn from the scattering experiment.

- **Option D**: "Atoms can exist with a series of discrete energy levels."
- This concept was not established by Rutherford; it was later developed by Niels Bohr. Therefore, this option is incorrect in the context of Rutherford's findings.

3. **Conclusion**: Based on the analysis, the only option that Rutherford's gold foil experiment supported is Option B: "The force of repulsion between an atomic nucleus and an alpha particle varies with distance according to inverse square law."

### Final Answer:
**Option B**: The force of repulsion between an atomic nucleus and an alpha particle varies with distance according to inverse square law.

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