What happens in nuclear fusion?

Two small nuclei join together to make a larger nucleus.

Nuclear Fusion is when two nuclei (the plural of nucleus) run into each other at a high speed. This makes them join together (fuse) to create one larger and heavier nucleus.

For example - two Hydrogen nuclei can collide to fuse into one Helium nucleus.

This process creates a lot of energy, which is released as radiation.

Nuclear Fusion reactions power the Sun and other stars. In a fusion reaction, two light nuclei merge to form a single heavier nucleus. The process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei. The leftover mass becomes energy.