This question contains Statement - 1 and Statement -2 Of the four choice given after the Statements , choose the one that best decribes the two Statements
Statement- 1:
Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion and
Statement- 2:
for nuclei , Binding energy nucleon increases with increasing `Z` while for light nuclei it decreases with increasing `Z`

Options

A. Statement-1 is false, Statement-2 is true.
B. Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for Statement-1.
C. Statement-1 is ture, Statement-2 is a correct explanation for Statement-1.
D. Statement-1 is true, Statement-2 is false.

Answer

To solve the question, we need to analyze the two statements provided and determine their validity and relationship.

### Step 1: Analyze Statement 1
**Statement 1:** Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion.

- **Fission:** In nuclear fission, a heavy nucleus splits into two or more lighter nuclei, releasing energy. This occurs because the binding energy per nucleon of the products is greater than that of the reactants.
- **Fusion:** In nuclear fusion, light nuclei combine to form a heavier nucleus, also releasing energy. This is because the binding energy per nucleon of the resulting heavier nucleus is greater than that of the individual light nuclei.

**Conclusion:** Statement 1 is true.

### Step 2: Analyze Statement 2
**Statement 2:** For nuclei, binding energy per nucleon increases with increasing Z (atomic number) while for light nuclei it decreases with increasing Z.

- **Binding Energy per Nucleon:** The binding energy per nucleon is a measure of the stability of a nucleus. For heavy nuclei, as Z increases, the binding energy per nucleon tends to increase due to the strong nuclear force overcoming the electrostatic repulsion between protons.
- **Light Nuclei:** For light nuclei, as Z increases, the binding energy per nucleon can decrease due to the increasing repulsive forces among protons, which are not sufficiently compensated by the strong nuclear force.

**Conclusion:** Statement 2 is also true.

### Step 3: Relationship Between the Statements
- Statement 1 is supported by the concept of binding energy discussed in Statement 2. The energy release during fission and fusion can be explained by the changes in binding energy per nucleon as described in Statement 2.

### Final Conclusion
Both statements are true, and Statement 2 provides a correct explanation for Statement 1. Therefore, the best choice that describes the relationship between the two statements is:

**Option B:** Both statements are true and Statement 2 is the correct explanation for Statement 1.

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