Question

Energy is released in both nuclear fission and fusion because:

• A. The total mass before and after the reaction remains the same.
• B. The mass of the products is less than the mass of the reactants.
• C. Energy is not related to mass change.
• D. Both reactions involve a change in atomic number.

Answer 1

The Correct Option is B

To address this problem, we must examine the underlying cause of energy release in nuclear fission and fusion, referencing the provided choices.

1. Mass-Energy Equivalence in Nuclear Processes:

- Nuclear reactions entail transformations within atomic nuclei.
- Einstein's equation, \( E = mc^2 \), illustrates the conversion of mass into energy.
- The diminution in mass from reactants to products, known as the mass defect, is transmuted into released energy.

2. Evaluation of Options:

• Option 1: "The total mass before and after the reaction remains the same." - Incorrect. A portion of the mass is converted into energy.
• Option 2: "The mass of the products is less than the mass of the reactants." - Correct. This mass difference (mass defect) is converted into energy, resulting in energy release.
• Option 3: "Energy is not related to mass change." - Incorrect. Energy release is a direct consequence of mass alteration.
• Option 4: "Both reactions involve a change in atomic number." - Not universally applicable, and not the fundamental reason for energy release.

Conclusion:

Nuclear fission and fusion release energy because the mass of the resulting products is less than the mass of the initial reactants.