Polonium monoxide

Within the sulfur sub-group, there are two main types of oxides, the dioxides X 02 (X = S, Se, Te, Po) and the trioxides X Os (X = S, Se, Te). In addition, sulfur also forms disulfur monoxide, S2O. Transient XO species are known in the gaseous phase for S, Se, and Te. Polonium forms a black monoxide PoO. 

Cigarette smoke contains a minute amount of polonium, along with many other carcinogenic chemicals, many of which can cause lung cancer. Over one hundred trace elements and compounds have been identified in cigarette smoke besides polonium. Some examples are nicotine, cresol, carbon monoxide, pyridine, and the carcinogenic compound benzopyrene. 

Platinum Dichloride Platinum Dioxide Platinum Hexafluoride Platinum Monoxide Platinum Tetrachloride Plutonium Polonium Potassium Potassium Acetate Potassium Bicarbonate Potassium Bisulfide Potassium Borohydride Potassium Bromate Potassium Bromide Potassium Carbonate... 

The black monoxide appears to be formed by the spontaneous decomposition of polonium sulfotrioxide and selenotrioxide (10). The corresponding hydroxide (or hydrated oxide) is obtained as a dark brown precipitate when alkali is added to a freshly prepared solution of bipositive polonium (6). Both are rapidly oxidized to polonium(IV) in air or in contact with water. 

---