Pierre Curie

French physicist, Nobel Prize laureate (d. 1906)

Marie and Pierre Curie announce the isolation of radium.

Marie und Pierre Curie berichten über die Entdeckung eines neuen Elements, das sie Polonium nennen.

Marie und Pierre Curie entdecken das chemische Element Radium.

Es descubierto el elemento químico polonio, por Pierre Curie y Marie Curie.

Radium was discovered by Marie Curie and her husband Pierre on 21 December 1898, in a uraninite sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to bismuth from pitchblende in July 1898, that turned out to be polonium. They then separated out a radioactive mixture consisting mostly of two 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, radium. 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 (ray): this was in recognition of radium's power of emitting energy in the form of rays.

French physicist and academic, Nobel Prize laureate (b. 1859)