I think you're talking about the Second Law of Turnipdynamics.
Anyway, Brian Cox told me that an electron has a mass that is approximately 1/1836 that of the proton, and the intrinsic angular momentum of the electron is a half-integer value in units of ħ, which he recons means that it is a fermion or some such. The antiparticle of the electron is called the positron which is identical to the electron except that it carries electrical and other charges of the opposite sign. My mate George, down the pub recons that when an electron collides with a positron, both particles are totally annihilated, producing gamma ray photons, and you dont want to be anywhere nearby when that kicks off.
Wait til I see mr Lyons for telling me it's like water in a pipe. Hold on, that was 45 years ago and he must be about 120 years old by now.