a. Explain what is meant by nuclear fusion and explain why it only occurs at very high temperatures.
b. The main reactions that fuel the Sun are the fusion of hydrogen nuclides to form helium nuclides. However, other reactions do occur. In one such reaction, known as the triple alpha process, three helium nuclei collide and fuse to form a carbon-12 nucleus.
i. Explain why temperatures higher than those required for the fusion of hydrogen are needed for the triple alpha process.
ii. Calculate the energy released in the triple alpha process.
(Mass of a helium (⁴₂He) nucleus = 4.001506 u, mass of a carbon (¹²₆C) nucleus = 12.000000 u, 1 u = 1.660 × 10⁻²⁷kg.)