An elementary particle is one step above a kindergarten particle. It is a particle that everyone who believes in pseudoscience pretends to be unbreakable by any force known to mankind. The only force that may be able to break an elementary particle is the Force ...
A Brief History of Dumbass Scientists
A long bit ago, some dudes in lab coats believed in kindergarten particles. Historians really cannot blame them, because, at the time, Macaulay Culkin was popular and people believed that Bill Clinton was a good president. These were called Dark Ages or the 1990s. Throughout the universe, however, progress was being made.
The Vulcans used to think that atoms were unbreakable until the Romulans broke them. Then they thought that protons, electrons, and neutrons were unbreakable until the Quarks broke them, and then we thought quarks were unbreakable.
Modern Synthesis of Elementary Particles: Welcome to your Particle Physics Overlords
Now, bosons, or the bad motherfuckers of the Universe, are believed to be unbreakable, but scientists are trying to find but so far are unsuccessful in finding the almighty gravitons. These scientists think about wonderfully strange things like comptons, neutrinos, muons, taus, gluons, and photoms.
Elementary particles develop to become high-school particles, then universal particles, and eventually become graduated particles. Sometimes high-school and universal particles quit before graduating and become drop-out particles.