Nuclear chemistry

All of the materials that we see are made from chemical elements, but where are elements made?

All of the naturally-occurring elements on planet Earth were made inside stars. Stars themselves mostly consist of hydrogen, the smallest and lightest of all the elements. Stars are gigantic nuclear furnaces, and can join together protons, neutrons and electrons to form larger elements. This process is called nuclear fusion.

When large stars grow old and die they firstly expand, becoming much larger, before exploding. Red supergiant stars that explode are called supernovae. Our local star, the sun, is not large enough to become a supernova and will expand to form a red giant before collapsing in on itself. Supernova explosions eject all of the elements that have been formed inside the star out into the universe. Over long periods of time, these elements can combine to form molecular clouds and eventually new planets and even new stars.