-Bombarded Beryllium with alpha particles and discovered that it emitted a stream of radiation. This stream was originally thought to be gamma radiation, but he later learned that like gamma rays, these rays were neutral. However, unlike gamma rays, these rays did not discharge charged electroscopes. Chadwick proposed that this particle was a neutron. awarded the Nobel Prize for his discovery. -Chadwick was able to determine the velocity of the protons using kinematics -Determined that the mass of the neutron was almost exactly the same as that of a proton
