Fundamental Charges
When we break matter up, we find there are just a few fundamental particles: electron, proton and neutron. (We’ll consider whether these are really fundamental or not in the last part of this course.)
electron: qe = -1.6 x 10-19 Coul; me = 9.1 x 10-31kg
proton: qp = +1.6 x 10-19 Coul; mp = 1.67 x 10-27kg
neutron: qn = 0; mn = 1.67 x 10-27kg
(note: despite what appears above, the mass of neutron and proton are NOT exactly the same; the neutron is slightly heavier; however, the charge of the proton and electron ARE exactly the same - except for sign)