The smallest particle is the muon neutrino. The subatomic particles are not measured in size; they are measured in energy. The muon neutrino has an energy of less than 0.170 MeV/c2.
All living things are made up of cells. Because they are small in size does not mean that their cell size is small. Generally cells are the same size between organisms.
Small businesses remain small for different reasons. They are almost always privately owned, some by couples, brothers, father and son, etc "ma and pa" organizations as they used to be called, where...