Which scientist devised an experiment that demonstrated the existence of the neutron?

James Chadwick is recognized for his groundbreaking experiment that provided evidence for the existence of the neutron. In 1932, he conducted experiments that involved bombarding beryllium with alpha particles, which led to the emission of a neutral radiation that could penetrate matter more than alpha or beta radiation. This neutral radiation was later identified as neutrons, demonstrating that not all atomic particles carry a charge and that neutrons are a fundamental component of the atomic nucleus.

Chadwick's discovery was significant because it helped to explain the previously observed discrepancies in atomic mass and stability in various elements, as well as aided in understanding nuclear reactions and the structure of the atomic nucleus. His work built upon earlier findings in particle physics but was unique in its direct proof of the existence of neutrons as distinct particles within the atom.