Marie Curie doubt, the Curies sought to isolate polonium and radium in pure form. Pitchblende is a complex mineral; the chemical separation of its constituents was an arduous task. The discovery of polonium had been relatively easy; chemically it resembles the element bismuth, and polonium was the only bismuth-like substance in the ore. Radium, however, was more elusive; it is closely related chemically to barium, and pitchblende contains both elements. By 1898 the Curies had obtained traces of radium, but appreciable quantities, uncontaminated with barium, were still beyond reach. The Curies undertook the arduous task of separating out radium salt by differential
Polonium trioxide radioactive. Similar work with curium shows that it is easier to achieve higher oxidation states with longer-lived isotopes; thus, it may be easier to obtain Po(VI) (especially polonium trioxide) using the longer-lived polonium-208 or polonium-209. It has been suggested that Po(VI) might be more stabilized in anions such as or , like other high oxidation states. 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