Inside the nucleus
Tap any atom in the 3D view to look inside it.
A proton is 2 up quarks + 1 down quark: +⅔ +⅔ −⅓ = +1 charge. A neutron is 1 up + 2 down: +⅔ −⅓ −⅓ = 0. Gluons bind the quarks, and the strong force holds protons and neutrons together.
A real nucleus is about 100,000 times smaller than its atom, so it is enlarged here.