Chemical Element: radon

(Modern Latin: from radium and argon, its chemical cousin; radioactive gas)

Chemical-Element Information

Symbol: Rn
Atomic number: 86
Year discovered: 1900

Discovered by: Friedrich Ernst Dorn (1848-1916), a German physicist.


  • Friedrich Ernst Dorn, while studying the radium that the Curies had discovered, found in 1900 that it gave off not only radiations but a gas that was itself radioactive.
  • The gas was called “radium emanation” at first, but on closer study it turned out to be a noble gas, the sixth one, and was named “radon”.
  • Dorn, apparently also called it “niton” after “the element radium” (radon was called “niton” because it was based on the Latin word, nitens, meaning “shining, bright, glittering”).
  • Because of its transient existence, radon is found only in conjunction with a source of radium.
  • The atmosphere contains traces of radon near the ground as a result of seepage from soil and rocks, all of which contain minute quantities of radium.

Name in other languages:

French: radon

German: Radon

Italian: radon (emanio)

Spanish: radón


Information about other elements may be seen at this Chemical Elements List.

A special unit about words that include chemo-, chem- may be seen here.