polonio

Polonium, symbol Po, atomic number 84, is a rare, highly radioactive post-transition metal in the chalcogen group. All of its isotopes are radioactive and there is no stable isotope. The most widely known isotope is polonium-210, with a half-life of about 138 days. Polonium occurs only in trace amounts in uranium ores as a decay product of uranium-238 and is not found free in nature.

Discovered in 1898 by Marie and Pierre Curie in pitchblende residues, polonium was named after Poland (Polonia) to honor the Curies’ homeland and Polish science.

Production of Po-210 is usually achieved by irradiating bismuth-209 in a nuclear reactor to form bismuth-210, which beta decays to Po-210. Polonium is an extremely radiotoxic alpha emitter; even tiny amounts can be dangerous if ingested or inhaled, and handling requires specialized facilities and strict containment.

Uses have been limited due to safety concerns but historically included static electricity neutralization in industry and small heat sources for certain radioisotope devices. Today Po-210’s use is highly regulated; it is primarily produced for niche scientific and industrial applications under strict controls.