James discovered the neutron in atoms. James discovered this subatomic particle by using a neutron chamber in his experiments. Chadwick carried out an experiment in which a sample of Beryllium was bombarded with alpha particles, which caused it to emit this radiation. He assumed it was gamma rays. He then discovered that this radiation, upon striking Paraffin Wax would dislodge some of the protons, coming to the conclusion it was gamma rays. Chadwick, however did not believe that gamma rays could account for the protons from the wax. He was convinced that the beryllium was emitting neutrons. Chadwick could tell that the mysterious radiation was neutral because it was not deflected by electric or magnetic fields and it did not invoke the photoelectric effect, unlike standard gamma radiation. This was when photons such as gamma rays, strike certain surfaces, they discharge electrons. However it discharged protons, which meant that the particles had to be more massive than previously expected. Therefore also coming to the conclusion that neutrons had a heavier mass than protons.