Question

The binding energy of deuteron is $2.2 \,MeV$ and that of $_{2}^{4}He$ is $28 \,MeV$. If two deuterons are fused to form one $_{2}^{4} He$, then the energy released is

• A. 25.8 MeV
• B. 23.6 MeV
• C. 19.2 MeV
• D. 30.2 MeV

Answer 1

Answer: (B)

23.6 MeV

Answer 2

The reaction can be written as ${ }_{1} H^{2}+{ }_{1} H^{2} \rightarrow{ }_{2} H e^{4}+$ energy The energy released in the reaction is difference of binding energies of daughter and parent nuclei. Hence, energy released = binding energy of ${ }_{2} H e^{4}-2 \times$ binding energy of ${ }_{1} H^{2}$ $=28-2 \times 2.2=23.6 \,MeV$