Nuclear fusion

Nuclear fusion is a change involving nuclei, not the electrons around them. During fusion, two light nuclei join to form one heavier nucleus.

In nuclear fusion, two small, light nuclei join to make a larger nucleus. This also releases energy. For example, hydrogen nuclei can fuse to form a helium nucleus.

In nuclear fusion, two light nuclei join to form a heavier nucleus. This is the opposite of nuclear fission, in which a nucleus splits. Fusion occurs in stars, including the Sun: through a sequence of reactions, hydrogen nuclei combine to form helium.

Nuclear fusion is the joining of two light nuclei to form a heavier nucleus. For example, hydrogen nuclei can combine in fusion processes that form helium nuclei. Because nuclei are positively charged, they repel one another, so they must be brought extremely close together; very high temperatures provide nuclei with the kinetic energy needed for this to happen.