Radium seventh of a gram of radium. One kilogram of the Earth's crust contains about 900 picograms of radium, and one liter of sea water contains about 89 femtograms of radium. Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninite (pitchblende) 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
Polonium trioxide Polonium trioxide Polonium trioxide (also known as polonium(VI) oxide) is a chemical compound with the formula PoO. It is one of three oxides of polonium, the other two being polonium monoxide (PoO) and polonium dioxide (PoO). It is an interchalcogen. It has so far only been detected in traces. It has been reported that trace quantities of polonium trioxide form during the anodic deposition of polonium from acidic solutions; although there is no experimental evidence for this, the fact that the deposit dissolves in hydrogen peroxide suggests that it contains polonium in a high oxidation state. It has been predicted