What goes on inside a proton?

[DreamGypsy]

3. Yes, all protons consist of 2 up quarks and 1 down quark....

... but neutrons, the other nucleon particle, consist of 2 down quarks and 1 up quark.

An up quark has a positive electric charge equal to 2/3 the magnitude of the charge of an electron; a down down quark has a negative electric charge equal to 1/3 the magnitude of the charge of an electron. This means the charge of the proton is equal in magnitude and opposite in sign to the electron (2/3 + 2/3 -1/3 = 1) and the neutron is electrically neutral (2/3 -1/3 -1/3 = 0).

There are other more exotic hadrons, that is particles made up of quarks and held together by the strong force.