Pions

Pions are subatomic particles that act as messengers between other particles called nucleons (protons and neutrons) within an atom's nucleus. They are a type of meson, which means they are made up of a quark and an antiquark. Pions help mediate the strong nuclear force, which binds protons and neutrons together, overcoming their electromagnetic repulsion. They are unstable and decay quickly, but play a crucial role in the interactions that keep atomic nuclei intact. In essence, pions are essential components of the forces holding matter together at the most fundamental level.