Choose the statement which is true.

Options

A. The energy released per unit mass is more in fission than in fusion
B. The energy released per atom is more in fusion than in fission.
C. The energy released per unit mass is more in fusion and that per atom is more in fission.
D. Both fission and fusion produce same amount of enrgy per atom as well as per unit mass.

Explanation

To determine which statement is true regarding the energy released in nuclear fission and fusion, we can analyze the information provided.

### Step-by-Step Solution:

1. **Understanding Fission and Fusion**:
- **Fission** is the process where a heavy nucleus splits into two or more lighter nuclei, releasing energy.
- **Fusion** is the process where two light nuclei combine to form a heavier nucleus, also releasing energy.

2. **Energy Released per Unit Mass**:
- In general, fusion reactions release more energy per unit mass compared to fission reactions. This is because the binding energy per nucleon is greater in the products of fusion than in the products of fission.

3. **Energy Released per Atom**:
- Energy released per atom in fusion is typically higher than in fission. For example, the fusion of hydrogen into helium releases significantly more energy than the fission of uranium or plutonium.

4. **Comparing the Statements**:
- The statements provided can be summarized as follows:
- A: Energy released per unit mass is more in fission than fusion.
- B: Energy released per atom is more in fusion than in fission.
- C: Energy released per unit mass is more in fusion than per atom in fission.
- D: Both fission and fusion produce the same amount of energy per atom as well as per unit mass.

5. **Evaluating the Statements**:
- Statement A is false because fusion releases more energy per unit mass.
- Statement B is true as fusion generally releases more energy per atom.
- Statement C is misleading; while fusion releases more energy per unit mass, it does not compare directly to fission in that way.
- Statement D is false; fission and fusion do not produce the same energy outputs.

6. **Conclusion**:
- The true statement among the options is **B: Energy released per atom is more in fusion than in fission**.

### Final Answer:
The correct statement is **B: Energy released per atom is more in fusion than in fission**.