Question

If a star can convert all the He nuclei completely into oxygen nuclei. The energy released per oxygen nuclei is [Mass of He nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu]. [IIT-JEE-2005]

• A. 7.6 MeV
• B. 56.12 MeV
• C. 10.24 MeV
• D. 23.9 MeV

Answer 1

The correct option is C 10.24 MeV

Energy released = change in rest energy = change in rest mass $\times c^2$
$\Rightarrow E=\frac{931}{c^2}\times \left(△mamu\right)\times c^2$
Now, 4He $\to$ 1O is the reaction
$\therefore perO,theE=931\times (4\times 4.0026-15.9994)$
= 931 \times 0.011 MeV
= 10.241 MeV