Radioactivity.
Aston, Francis William, 1877-1945
Becquerel, Henri, 1852-1908
Bohr, Niels, 1885-1962
Cherenkov, P. A.
Cockcroft, John, Sir, 1897-1967
Curie, Marie, 1867-1934
Curie, Pierre, 1859-1906
Duffield, Robert B.
Fermi, Enrico, 1901-1954
Helmholz, August Carl, 1915-2003
Hevesy, Georg von, 1885-1966
Joliot-Curie, Frédéric
Joliot-Curie, Irène
Nier, Alfred O. (Alfred Otto), 1911-1994
Walton, Ernest, 1903-1995