|MadSci Network: Physics|
There are three kinds of subatomic particles that commonly exist in nature: protons, neutrons and electrons. There are many others, but they are not stable. Protons and neutrons are bags of quarks (three each) held together by gluons. Protons and neutrons are not round, but instead lumpy-- although it's rather hard to really see what shape they are. They are very small (10^ -12 meters across!). Quarks and electrons are, to the best of our knowledge, point particles. That means they are as small as you can get! Nothing makes them up. We are doing experiments to see if that is true.
Try the links in the MadSci Library for more information on Physics.