| MadSci Network: Physics |
A particle can only annihilate with its own antiparticle, so that an electron and proton cannot annihilate each other. The lowest possible state of an electron and a proton is the normal hydrogen atom. A particle called the "positron" is the antiparticle of the electron and they do eventually annihilate when a positron and an electron attract each other.
[note added by MadSci Admin: See
Particle Adventure for a lot of
good information about fundamental particles!]
Try the links in the MadSci Library for more information on Physics.