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32.5 Exercise 19

Avg difficulty 2.5

Another set of reactions that result in the fusing of hydrogen into helium in the Sun and especially in hotter stars is called the carbon cycle. It is
12 C + 1 H → 13 N + γ , 13 N → 13 C + e + + v e , 13 C + 1 H → 14 N + γ , 14 N + 1 H → 15 O + γ , 15 O → 15 N + e + + v e , 15 N + 1 H → 12 C + 4 He. \begin{matrix}^{\text{12}} \text{C} + ^{1} \text{H } & \rightarrow & ^{\text{13}} \text{N} + \gamma , \\ ^{\text{13}} \text{N } & \rightarrow & ^{\text{13}} \text{C} + e^{+ } + v_{e} , \\ ^{\text{13}} \text{C } + ^{1} \text{H } & \rightarrow & ^{\text{14}} \text{N} + \gamma , \\ ^{\text{14}} \text{N} + ^{1} \text{H } & \rightarrow & ^{\text{15}} \text{O} + \gamma , \\ ^{\text{15}} \text{O } & \rightarrow & ^{\text{15}} \text{N} + e^{+ } + v_{e} , \\ ^{\text{15}} \text{N} + ^{1} \text{H } & \rightarrow & ^{\text{12}} \text{C} + ^{4} \text{He}.\end{matrix}
Write down the overall effect of the carbon cycle (as was done for the proton-proton cycle in 2e−+4 1 H→ 4 He+ 2ve +6γ 2 e^{- } + 4 ^{1} \text{H} \rightarrow ^{4} \text{He} + \left(2 v\right)_{e} + 6γ). Note the number of protons ( 1H^{1} \text{H}) required and assume that the positrons ( e+e^{+ }) annihilate electrons to form more γ\gamma rays.

OpenStax College Physics 2e, 32.5 Fusion, exercise 19

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