Atoms are the basic building blocks of matter. They can effectively join together to form molecules, which in turn shape everything you see around you in the physical world.
Each atom is composed of subatomic particles called protons, electrons and neutrons. The protons and neutrons cluster together within the central part of the atom known as the nucleus, while the electrons orbit around this nucleus at a frantic speed.
Both protons and neutrons are composed of even smaller particles known as quarks and gluons.