Chadwick, Sir James (1891-1974), a British physicist, won the 1935 Nobel Prize in physics for his discovery of the neutron, one of the particles making up the nucleus of an atom. In 1924, Chadwick became assistant director of the Cavendish Laboratory in Cambridge, England, where he worked closely with the physicist Ernest Rutherford. The two scientists bombarded various chemical elements with alpha particles (see Alpha particle ). Chadwick studied how these elements were transmuted (changed) into different ones. This work led him to discover the neutron and determine its mass (see Neutron ). Born on Oct. 20, 1891, near Manchester, England, Chadwick studied at the University of Manchester and in Berlin. He died on July 24, 1974.
See also Rotblat, Joseph .
