Question

Assertion (A): Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion.

Reason (R): For heavy nuclei, binding energy per nucleon increases with increasing Z while for light nuclei, it decreases with increasing Z.

पर्याय

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

• Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

• Assertion (A) is true, but Reason (R) is false.

• Both Assertion (A) and Reason (R) are false.

Answer 1

Assertion (A) is true, but Reason (R) is false.

Explanation:

The assertion is true. Fission of very heavy nuclei and fusion of very light nuclei release energy because the products have higher binding energy per nucleon (net increase in binding energy). The Reason is false. The binding energy per nucleon actually rises from light nuclei up to a peak (around mid-mass like Fe) and then falls for heavier nuclei, so the reasons stated are incorrect.