Final answer:
The fusion of light elements, such as hydrogen, releases energy. This process powers the sun and other stars as well. When two hydrogen nuclei combine, they form an unstable helium nucleus and release a significant amount of energy.
Step-by-step explanation:
The fusion of light elements, such as hydrogen, releases energy. This process is what powers the sun and other stars. When two hydrogen nuclei, or protons, combine, they form an unstable helium nucleus and release a significant amount of energy. This energy is a result of the conversion of mass into energy, as the mass of the helium nucleus is slightly less than the combined mass of the two hydrogen nuclei.