The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and ...

Atoms are in fact made up of three smaller particles called protons, electrons and neutrons. The protons and neutrons are contained in the nucleus, the tiny centre of an atom, with smaller ...

The question of what protons or neutrons are made up of has an apparently simple answer: quarks and gluons. However, when it comes to atoms’ third component, electrons, the answer is not as easy.

Since electrons have almost no mass, it seemed that something besides the protons in the nucleus were adding to the mass. One leading explanation was that there were electrons and additional ...

The atom is a complex system of particles. It's made up of a central nucleus consisting of protons and neutrons, called ...