How was the neutron discovered by James Chadwick?

In 1932, British physicist James Chadwick discovered the neutron by conducting experiments that challenged existing hypotheses regarding atomic radiation.1

Prior to his discovery, French physicists Frédéric and Irène Joliot-Curie had observed that bombarding beryllium with alpha particles produced an unknown, highly penetrating radiation, which they hypothesized to be gamma-rays. Chadwick, however, was convinced that alpha particles lacked the energy required to generate such powerful gamma radiation.1

By performing his own beryllium bombardment experiments, Chadwick interpreted the resulting radiation not as gamma-rays, but as a stream of neutral particles. He determined that these particles possessed a mass approximately equal to that of a proton but carried no electric charge. This identification of the neutron provided a critical missing piece in the understanding of atomic structure, confirming that the nucleus is composed of both protons and neutrons.123