Which of the following conclusions could not be derived from Rutherford's α-particle scattering experiment?

Options

A. Most of the space in the atom is empty.
B. The radius of the atom is about `10^(-10)`m while that of nucleus is `10^(-15)`m.
C. Electrons move in a circular path of fixed energy called orbits.
D. Electrons and the nucleus are held together by electrostatic forces of attraction.

Answer

To determine which conclusion could not be derived from Rutherford's α-particle scattering experiment, we need to analyze the conclusions that were indeed drawn from the experiment and identify the one that does not align with Rutherford's findings.

### Step-by-Step Solution:

1. **Understanding Rutherford's Experiment**:
- Rutherford conducted an experiment where he bombarded a thin gold foil with α-particles (helium nuclei). Most of the α-particles passed straight through the foil, while a small number were deflected at various angles, and a very few were reflected back.

2. **Conclusions from the Experiment**:
- **Conclusion 1**: Most of the atom is empty space. This was concluded because most α-particles passed through without deflection.
- **Conclusion 2**: The nucleus is very small compared to the size of the atom. This was inferred from the fact that only a few particles were deflected, indicating a small, dense center (the nucleus).
- **Conclusion 3**: The nucleus contains positively charged protons. This is implied from the deflection of positively charged α-particles by the nucleus.
- **Conclusion 4**: Electrons are held in orbit around the nucleus by electrostatic forces of attraction. This conclusion was not derived from Rutherford's experiment; it was later proposed by Bohr.

3. **Identifying the Incorrect Conclusion**:
- Among the options provided, the statement that "electrons move in a circular path of fixed energy called orbits" is not a conclusion that can be drawn from Rutherford's experiment. This concept was introduced by Niels Bohr in his atomic model.

4. **Final Answer**:
- The conclusion that could not be derived from Rutherford's α-particle scattering experiment is that "electrons move in a circular path of fixed energy called orbits."