The energy output of massive stars is believed to be due to the carbon cycle (see text).
(a) Show that no carbon is consumed in this cycle and that the net effect is the same as for the proton-proton cycle.
(b) What is the total energy release?
(c) Determine the energy output for each reaction and decay.
(d) Why does the carbon cycle require a higher temperature (≈ 2 x 107 K) than the proton-proton cycle (≈ 1.5 x 107 K)?