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"
James Chadwick with no electric charge. Then in January 1932, Feather drew Chadwick's attention to another surprising result. Frédéric and Irène Joliot-Curie had succeeded in knocking protons from paraffin wax using polonium and beryllium as a source for what they thought was gamma radiation. Rutherford and Chadwick disagreed; protons were too heavy for that. But neutrons would need only a small amount of energy to achieve the same effect. In Rome, Ettore Majorana came to the same conclusion: the Joliot-Curies had discovered the neutron but did not know it. Chadwick dropped all his other responsibilities to concentrate on proving the existence of