An interesting and deep question. The standard model says that the 3 quarks at the core of a proton are UDU or Up=+2/3 Down=-1/3 Up=+2/3 or +2/3-1/3+2/3=3/3=+1 positive charge; and the neutron is a DUD or Down=-1/3 Up=+2/3 Down=-1/3 or -1/3+2/3-1/3=0. Thus the neutron has zero electrical charge but because the interior quarks are still spinning around, by Maxwell's +dE/dt term in his 4th equation, the neutron still has a magnetic moment. This shows up in the helium 3 nucleus which has 2 protons but only 1 neutron, thus it has a magnetic moment; whereas the helium 4 nucleus has 2 neutrons and thus they magnetically cancel out; the entire helium 4 atom is thus completely inert, charge-wise, chemically, magnetically; basically 3 balanced-out bosons<2 electrons, 2 protons, 2 neutrons>. At a deeper level there was 2 people about a century ago, Ledbetter and Bezant, who used micro-psi to actually see atoms(with matter waves), quarks, even sub-quarks which they said are made up of STRINGS : 3 bright lines+7 rainbow colored lines in an involuting/evoluting torus form, sort of like a solenoid coil, alive, vibrating, beating like a heart; and with 4/9ths, 5/9ths fractional charges<weird stuff>. Then there's the quantum Hall effect with its strange 2/7ths, 4/5ths, etc fractional charges associated with matter waves. Then there's the MEG theory of split dipoles...so that's a deep, deep question you've asked. Keep at it, nobody but GOD actually knows what "charge" IS, we know a LOT about it, but we still don't know what it really IS, maybe you're the one that eventually puts it all together.

_________________________

timer