Final answer:
The Sun's energy is generated through nuclear fusion where hydrogen nuclei are fused into helium, converting mass into vast amounts of energy. This process happens due to the high temperatures in the Sun's core and is more powerful than nuclear fission or chemical combustion.
Step-by-step explanation:
The Sun's prodigious energy output is primarily the result of nuclear fusion occurring in its core. Solar energy is produced through a series of fusion reactions known as the proton-proton chain, where four hydrogen nuclei (protons) are converted into one helium nucleus. During this process, a fraction of mass is lost, which is transformed into a tremendous amount of energy, according to the famous equation E = mc².
This energy production mechanism occurs at very high temperatures, around 14 million Kelvin in the Sun's core, and involves the emission of various particles, including photons, neutrinos (which barely interact with matter and escape almost immediately), and positrons. While the energy output from the center of the Sun travels slowly to the surface, fusion itself occurs at the boundary of the helium core where the temperature and pressure are sufficient to sustain the reactions.
The amount of energy released during the fusion of hydrogen into helium—around 3.6 × 10¹¹ kJ per mole of helium—is significantly greater than the energy from other nuclear reactions, like the fission of uranium or the chemical combustion of hydrocarbons. Nuclear fusion not only powers the Sun but also presents potential for a future clean energy source on Earth.