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 dioxide reaction of polonium dioxide with potassium hydroxide or potassium nitrate in air gives the colourless potassium polonite (KPoO): Polonium dioxide is closely related to the polonite anion (), similar to the relationship between polonium trioxide and the polonate anion (). Polonium dioxide has no uses outside of basic research. All polonium compounds, such as polonium dioxide, are extremely radioactive and thus must be handled in a glove box. The glove box must further be enclosed in another box similar to the glove box, maintained at a slightly lower pressure than the glove box to prevent the radioactive materials from leaking