Polonium is a very rare radioactive element discovered by Mme. Curie in 1898. It also was the first element discovered by Mme. Curie. Polonium is so rare, that there are only approximately 100 micrograms of it per ton of Uranium. It is possible, however, to create very small amounts of polonium by bombarding natural Bismuth (209Bi) with neutrons. There are 25 known isotopes of polonium, with atomic masses ranging from 194 to 218. Polonium-10 is the easiest to obtain. Also, isotopes of mass 209 and 208 can be produced by alpha, proton, or deuteron bombardment of bismuth. Polonium radiation gives off alpha particles, but it is extremely dangerous, and must be handled with utmost care. Even milligrams or micrograms of polonium can have a devastating effect on human tissue.