Which kind of nuclear reaction is the source of the sun's energy?

Options

A. nuclear fission
B. nuclear fusion
C. Both nuclear fission and fusion
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Nuclear Reactions**: There are two main types of nuclear reactions: nuclear fusion and nuclear fission.
- **Nuclear Fusion**: This is the process where small atomic nuclei combine to form a larger nucleus.
- **Nuclear Fission**: This is the process where a large atomic nucleus splits into smaller nuclei.

2. **Identifying the Reaction in the Sun**: The Sun primarily consists of hydrogen, which has small nuclei. The conditions in the Sun, particularly its extremely high temperature (approximately 1.5 x 10^7 K), facilitate the fusion of hydrogen nuclei.

3. **The Fusion Process**: In the Sun, hydrogen nuclei (H) undergo fusion to form helium (He). The reaction can be summarized as:
- 4 hydrogen nuclei (4H) combine to form 1 helium nucleus (He) along with the release of energy and other particles (like gamma rays and neutrons).

4. **Energy Release**: The fusion of hydrogen into helium releases a significant amount of energy, which is the source of the Sun's energy. The energy released in this process is about 26.7 mega electron volts (MeV).

5. **Conclusion**: Therefore, the kind of nuclear reaction that is the source of the Sun's energy is nuclear fusion.

**Final Answer**: The source of the Sun's energy is nuclear fusion.

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