We consider them to be made of 3 quarks, 'uud' for the proton<span> and 'udd' for the</span>neutron<span> where 'u' is the up quark and 'd' the down quark. ... Now, </span>protons and neutrons<span> are basically found at the atomic nucleus while </span>electrons<span> form the shell of the atom, moving around the nucleus.</span>
