Fusion

Nuclear fusion is the joining of light nuclei to form a heavier nucleus, releasing energy. Fusion powers stars, including the Sun.

Light nuclei must come close enough for the strong nuclear interaction to become important. This requires extremely high temperatures and suitable conditions.

The mass of the final nucleus can be slightly less than the total mass of the original nuclei. The mass difference appears as energy: **E = mc²**

In stars, fusion reactions convert lighter nuclei into heavier nuclei and release large amounts of energy.

Scientists research controlled fusion as a possible future energy source. Creating and maintaining suitable conditions is technically very difficult.

Fission → heavy nucleus splits. Fusion → light nuclei join.