Answer to Question #143008 in Physics for Arvin Shopon

Question

Protons and neutrons are made up of quarks, which also have an electric charge. Find out how big the quark reserves are. Why is a neutron neutral? Why is the proton charge + e ?

Answer 1

Protons are made of two Up and one Down quark. The neutron is made of two Down and one Up quark. The Up quarks have a 2/3 positive charge and the Down has a 1/3 negative charge. Fractional charges are a pretty funny concept, but remember we (humans) made up the unit of charge that a proton has, so its very possible that there could be a smaller division of charge. If you add those charges you will see that sum is positive one for the proton and 0 for the neutron.