Polonium (Po)
Polonium: The Radioactive Alpha-Emitter
Polonium is a silvery-gray, semi-metal that is extremely rare and intensely radioactive. It emits powerful alpha particles, and just a tiny amount can generate enormous heat. The element was named by Marie Curie in 1898 after her homeland, Poland (Polonia), making it one of the first elements named for a country.
Why Is Polonium Useful?
Because of its incredible radioactivity, polonium has only a few very specialized uses:
Spacecraft Heaters: One gram of polonium can reach 500 °C just from radioactive decay. This heat was used to keep instruments warm on lunar rovers and spacecraft.
Neutron Source: When combined with beryllium, polonium becomes a useful neutron source for scientific research.
Antistatic Devices: Polonium has been used in antistatic brushes and devices, where alpha particles ionize the air and help neutralize electrical charges.
Biological Role & Natural Abundance
Polonium has no biological role. It is highly toxic—if inhaled or ingested, even microscopic amounts can be deadly due to its intense radioactivity.
Polonium occurs naturally in tiny traces within uranium ores, but extracting it this way is impractical. Instead, it is produced artificially by bombarding bismuth-209 with neutrons in a nuclear reactor. The bismuth turns into bismuth-210, which then decays into polonium.
History of Discovery
Predicted: Dmitri Mendeleev suspected an element should exist near bismuth on the periodic table.
Discovered (1898): Marie and Pierre Curie painstakingly processed tons of uranium ore (pitchblende) and managed to isolate a minute amount of a brand-new, intensely radioactive element—polonium.