Polonium
Definition and meaning of Polonium in chemistry.
Polonium is a highly radioactive and exceptionally rare metalloid with the chemical symbol Po and atomic number 84. It is an extremely dangerous element that emits intense alpha radiation and actively releases substantial amounts of thermal energy as it naturally decays.
In more detail
Polonium is positioned in group 16 of the periodic table, directly below tellurium, and exhibits chemical properties remarkably similar to both tellurium and bismuth. It occurs naturally in uranium ores in miniscule trace amounts, as it is a natural intermediate decay product of the common isotope uranium-238. All known isotopes of polonium are radioactive, with polonium-210 being the most widely available and extensively studied isotope, possessing a relatively short half-life of 138 days. The intense alpha radiation continuously emitted by polonium can rapidly destroy living biological tissue, making it one of the most toxic chemical substances known to humanity by weight. Because of its extreme natural scarcity and profound radioactivity, polonium has very few practical applications outside of highly specialized scientific, military, and industrial environments.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Po |
| Atomic number | 84 |
| Atomic mass | [209] u |
| Category | Metalloid |
| State at room temperature | Solid |
| Melting point | 254 °C (489 °F) |
| Year discovered | 1898 |
| Discoverers | Marie Curie and Pierre Curie |
Polonium-210 is sometimes used to eliminate static electric charges in specialized industrial machinery, in anti-static brushes for photographic film processing, and in thermoelectric radioisotope generators for space probes.
Frequently asked questions
How dangerous is polonium to humans?
Polonium is highly lethal if ingested, inhaled, or absorbed, because its intense internal alpha particle emission causes severe cellular destruction, DNA damage, and acute radiation poisoning.
How is polonium produced for industrial applications today?
Most commercial polonium is produced artificially by bombarding the element bismuth-209 with neutrons in a nuclear reactor, causing it to transmute into polonium.