Sadly, many schools teach their students that the smallest any piece of matter can be broken up into is an atom. Sometimes students will learn about the basics behind a proton, neutron, or an electron, but the fundamentals of those particles and the particles that make them up are rarely discussed in schools. Protons and neutrons are nucleons, baryons that are located in the nucleus of an atom. Baryons, including protons and neutrons, are made up of three different quarks, which are elementary particles that have not been broken up farther. There are six different kinds of quarks, but only two, the up quark (u) and the down quark (d), are needed to make nucleons. An up quark has an electromagnetic charge of +2/3, while a down quark has a charge of -1/3, so two up and one down quark create a charge of +1, and two down and one up create a neutral charge. Henceforth, a Proton consists of (uud) and a neutron consists of (udd).
From Wikipedia, created by Arpad Horvath
