Quarks and leptons
The neutrino is the fourth member of a family of four corpuscles which plays a fundamental role in the world around us. The first two are the quarks "up" and "down" components of nuclear matter, the third is the electron. Physicists call leptons the pair made of the electron and the neutrino. Quarks and leptons are tiny corpuscles to small to be ever observed in a microscope.In the figure , the quarks and leptons representation by spinning tops is of course symbolic.