Radium components: compounds of barium, which gave a brilliant green flame color, and unknown radioactive compounds which gave carmine spectral lines that had never been documented before. The Curies found the radioactive compounds to be very similar to the barium compounds, except that they were more insoluble. This made it possible for the Curies to separate out the radioactive compounds and discover a new element in them. The Curies announced their discovery to the French Academy of Sciences on 26 December 1898. The naming of radium dates to about 1899, from the French word "radium", formed in Modern Latin from "radius"
Polonium In the United States, polonium was produced as part of the Manhattan Project's Dayton Project during World War II. It was a critical part of the implosion-type nuclear weapon design used in the Fat Man bomb on Nagasaki in 1945. Polonium and beryllium were the key ingredients of the 'urchin' detonator at the center of the bomb's spherical plutonium pit. The urchin ignited the nuclear chain reaction at the moment of prompt-criticality to ensure the bomb did not fizzle. Much of the basic physics of polonium was classified until after the war. The fact that it was used as an