A) 26.7 MeV
B) 25.3 MeV
C) 22 MeV
D) 24.5 MeV
Correct Answer: A
Solution :
The proton-proton cycle by which this occurs is represented by the following sets of reactions \[_{1}^{1}H+_{1}^{1}H\to _{1}^{2}H+{{e}^{+}}+v+0.42\,MeV\] ... (i) \[{{e}^{+}}+{{e}^{-}}\to \gamma +\gamma +1.02\,\,MeV\] ... (ii) \[_{1}^{2}H+_{1}^{1}\to _{2}^{3}He+\gamma +5.49\,\,MeV\] ... (iii) \[_{2}^{3}H+_{2}^{3}\to _{2}^{4}He+_{1}^{1}H+_{1}^{1}H+12.86\,\,MeV\] ... (iv) For the fourth reaction to occur, the first three reactions must occur twice, if we consider the combination 2(i) + 2 (ii) + 2 (iii) + 2 (iv), the net effect is \[4_{1}^{1}H+2{{e}^{-1}}\to _{2}^{4}He+2v+6v+26.7\,MeV\] Thus, four hydrogen atom combines to form an \[_{2}^{4}He\] atom with a release of 26.7 MeV of energy.You need to login to perform this action.
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