Polonium initiator was classified until the 1960s. The Atomic Energy Commission and the Manhattan Project funded human experiments using polonium on five people at the University of Rochester between 1943 and 1947. The people were administered between of polonium to study its excretion. Polonium is a very rare element in nature because of the short half-life of all its isotopes. Po, Po, and Po appear in the decay chain of U; thus polonium can be found in uranium ores at about 0.1 mg per metric ton (1 part in 10), which is approximately 0.2% of the abundance of radium. The amounts
Polonium room temperature. Tetrahalides can be obtained by reacting polonium dioxide with HCl, HBr or HI. Other polonium compounds include potassium polonite as a polonite, polonate, acetate, bromate, carbonate, citrate, chromate, cyanide, formate, (II) and (IV) hydroxides, nitrate, selenate, selenite, monosulfide, sulfate, disulfate and sulfite. Oxides Hydrides Halides Polonium has 33 known isotopes, all of which are radioactive. They have atomic masses that range from 188 to 220 u. Po (half-life 138.376 days) is the most widely available and is made via neutron capture by natural bismuth. The longer-lived Po (half-life years, longest-lived of all polonium isotopes) and Po (half-life 2.9