A particle in an "indivisible" unit of matter. Particles are sometimes also called "fundamental particles." Examples of particles include the electron, muon, neutron, proton, etc., and the study of particles is known as particle physics. It should be noted that even "indivisible" particles may themselves be composed of subunits, e.g., hadrons consist of quarks. To each particle, there exists a similar particle known as the antiparticle.
Wave-particle duality, one of the most important concepts from quantum mechanics, states that particles have wave-like properties (e.g., the de Broglie wavelength), and conversely waves have particle-like properties (e.g., photons have momentum). The following list summarizes various indicators that ultimately led to the conclusion that that radiation has particle-like properties and comes in discrete packets of energy.
Antiparticle, Particle Decay, Particle Detector, Particle Physics, Wave-Particle Duality
