In the 5th century BC, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles called atoms
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which all other particles are made.
In the Standard Model, the elementary particles consist of the fundamental fermions and the fundamental bosons:
Fermions:
• Quarks (up, down, charm, strange, top, bottom)
• Leptons (electron, electron neutrino, muon, muon neutrino, tau, tau neutrino)Bosons:
• Gauge bosons (gluon, W and Z bosons, photon)
• Higgs bosonOf these, only the Higgs boson remains undiscovered, but efforts are being taken at the Large Hadron Collider to determine whether it exists or not.
Additional elementary particles may exist, such as the graviton, which would mediate gravitation. Such particles lie beyond the Standard Model.
