Final answer:
The Sun generates a massive quantity of energy through the process of nuclear fusion, where light nuclei combine to form heavier nuclei, releasing energy via mass-to-energy conversion.
Step-by-step explanation:
The sun's center produces a massive quantity of energy through a phenomenon known as nuclear fusion. Nuclear fusion is a process where two light atomic nuclei combine to form a heavier nucleus, releasing a large quantity of energy as a result of the mass-to-energy conversion described by Einstein's equation E=mc². In the core of the Sun, nuclear fusion occurs predominantly through the proton-proton cycle, wherein four hydrogen (1H) nuclei fuse into a single helium (4He) nucleus, releasing energy in the form of gamma rays and positrons.