Final answer:
Nuclear fusion is the process in which light atomic nuclei combine to form a heavier nucleus, releasing energy. It is prevalent in stars, where hydrogen nuclei fuse under extreme conditions to form helium, positrons, neutrinos, and gamma rays.
Step-by-step explanation:
The process in which two nuclei combine to form a single, larger nucleus, and release a tremendous amount of energy, is known as nuclear fusion. This reaction is energetically favorable for light nuclei and results in the formation of medium-mass nuclei. The energy released during nuclear fusion is significant and this phenomenon is the fundamental energy source in stars. An example of a fusion reaction that occurs within stars like our sun is the proton-proton cycle, which can be represented as:
- ¹H + ¹H → ²H + e+ + ve
- ¹H + ²H → ³He + y
- ³He + ³He → 4He + ¹H + ¹H
These reactions demonstrate how hydrogen nuclei (protons) combine under extreme temperatures to form helium, with positrons, neutrinos, and gamma rays (y) being emitted in the process.