An Introduction to Modern Astrophysics · Problem 10.13

The Sun — Carroll & Ostlie

Physics — Astrophysics · nuclear-reaction-q-values

Problem

Calculate the amount of energy released or absorbed in the following reactions (express your answers in MeV): (a)

{}^{12}_6\mathrm{C} + {}^{12}_6\mathrm{C} \rightarrow {}^{24}_{12}\mathrm{Mg} + \gamma

(b)

{}^{12}_6\mathrm{C} + {}^{12}_6\mathrm{C} \rightarrow {}^{16}_8\mathrm{O} + 2\,{}^4_2\mathrm{He}

(c)

{}^{19}_9\mathrm{F} + {}^1_1\mathrm{H} \rightarrow {}^{16}_8\mathrm{O} + {}^4_2\mathrm{He}

The mass of

{}^{12}_6\mathrm{C}

is 12.0000 u, by definition, and the masses of

{}^{16}_8\mathrm{O}

{}^{19}_9\mathrm{F}

, and

{}^{24}_{12}\mathrm{Mg}

are 15.99491 u, 18.99840 u, and 23.98504 u, respectively. Are these reactions exothermic or endothermic?