Nuclear fusion is possible

Options

A. Only between light nuclei
B. Only between heavy nuclei
C. Between both light and heavy nuclei
D. Only between nuclei which are stable against `beta`-decay.

Explanation

To determine the conditions under which nuclear fusion is possible, we need to understand the basic principles of nuclear fusion and how it differs from nuclear fission.

### Step-by-Step Solution:

1. **Understanding Nuclear Fusion**:
- Nuclear fusion is the process where two light atomic nuclei combine to form a heavier nucleus. This process releases a significant amount of energy.

2. **Comparison with Nuclear Fission**:
- Nuclear fission is the splitting of a heavy nucleus into two or more lighter nuclei, which also releases energy. This is the opposite of fusion.

3. **Conditions for Fusion**:
- Fusion typically occurs under extreme conditions of temperature and pressure, which allow the positively charged nuclei to overcome their electrostatic repulsion (Coulomb barrier).

4. **Types of Nuclei Involved**:
- Fusion is primarily observed with light nuclei, such as isotopes of hydrogen (deuterium and tritium). Heavy nuclei do not typically undergo fusion because they are more stable and tend to undergo fission instead.

5. **Stability Against Beta Decay**:
- Fusion is possible between nuclei that are stable against beta decay. This means that the nuclei involved in fusion should not be prone to spontaneous decay, which is more common in heavier nuclei.

6. **Conclusion**:
- Therefore, nuclear fusion is possible primarily between light nuclei, and it is not feasible with heavy nuclei due to their stability and the nature of the nuclear forces involved.

### Final Answer:
Nuclear fusion is possible primarily between light nuclei.

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