A proton is a
baryon
matter particle composed of two upsilon
quark and
one delta
quark. It has a net charge of +1, and a mass of 1.6727x10-24
grams. Most often it is found in the nucleus of atoms of all
periodic matter, but it can also exist as a free-floating ion. The
proton is the only
baryon
that is stable in isolation. It is the
antiparticle of an
antiproton.
