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 solve the problem, we need to analyze the reason behind energy release in nuclear fission and fusion based on the options provided.

1. Understanding Mass-Energy Relationship in Nuclear Reactions:

- Nuclear reactions involve changes in the nucleus of atoms.
- According to Einstein’s equation, \( E = mc^2 \), mass can be converted into energy.
- The difference in mass before and after the reaction is called the mass defect, which is released as energy.

2. Analyze the Options:

• Option 1: "The total mass before and after the reaction remains the same." - This is false, as some mass is lost and converted to energy.
• Option 2: "The mass of the products is less than the mass of the reactants." - This is true; the mass defect is converted to energy, causing energy release.
• Option 3: "Energy is not related to mass change." - False, energy release is directly related to mass change.
• Option 4: "Both reactions involve a change in atomic number." - Not necessarily true for all cases, and this is not the primary reason energy is released.

Final Answer:

Energy is released in both nuclear fission and fusion because the mass of the products is less than the mass of the reactants.