Which of the following is correct concerning subatomic particles? a) the electron was discovered by goldstein in 1886. b) the neutron was discovered by chadwick in 1932. c) the proton was discovered by thomson in 1880. d) cathode rays were found to be made of protons. how many neutrons and protons does a neutral atom of sodium with an atomic mass number of 23 have? a) 22 neutrons; 11 protons b) 23 neutrons; 11 protons c) 11 neutrons; 11 protons d) 12 neutrons; 11 protons