An [[atom]] is made of three particles, protons, [[neutron|neutrons]], and [[electron|electrons]]. Protons and [[neutron|neutrons]] make up the nucleus of the atom.<ref>Serway, Beichner: ''Physics for Scientists and Engineers'', 5th edition</ref> | An [[atom]] is made of three particles, protons, [[neutron|neutrons]], and [[electron|electrons]]. Protons and [[neutron|neutrons]] make up the nucleus of the atom.<ref>Serway, Beichner: ''Physics for Scientists and Engineers'', 5th edition</ref> |