Polonium is a chemical element in the periodic table that has the symbol Po and atomic number 84.
A rare and highly radioactive metalloid, polonium is chemically similar to tellurium and bismuth, and it occurs in uranium ores.
Polonium has been studied for possible use in heating spacecraft.
It exists as a number of radio-isotopes.
Weight-for-weight, polonium's toxicity is around 109 times greater than hydrogen cyanide.
The main hazard is its intense radioactivity.
Generally, Po is most lethal when it is ingested.