Chemical Element: radium

(Modern Latin: from Latin radius, meaning “ray”, because of its intense radioactivity; radioactive metal)

Chemical-Element Information


Symbol: Ra
Atomic number: 88
Year discovered: 1898

Discovered by: Marie Sklodowska Curie (1867-1934), Polish-born French chemist and Pierre Curie (1859-1906), French chemist and an assistant, G. Bémont, at the Sorbonne in Paris.


  • Marie Curie began the investigation of the new field of radiations produced by uranium (she coined the word “radioactivity”) and showed that it was indeed the uranium atom that was the source of the radiations.
  • Pierre Curie, recognizing the talent of his wife, abandoned his own researches and joined her in her work.
  • The Curies discovered that although pure uranium compounds were always radioactive only to the extent that uranium was present, some uranium ores produced far more radioactivity than could be accounted for by the uranium present.
  • It seemed to them that the ores must contain other elements (in small quantities or they would have been discovered earlier) that were much more intensely radioactive than uranium.
  • Radium was discovered, in 1898, by Marie and Pierre Curie in pitchblende (or uraninite) from North Bohemia.
  • In 1911, Marie alone was awarded the Nobel Prize for Chemistry for the discovery of polonium and radium.
  • She was the only one to receive the award because her husband, Pierre, was killed in a traffic accident in 1906 having been run over by a horse-drawn vehicle.
  • Radium was isolated, in 1911, by Mme. Curie and André-Louis Debierne (1874-1949) by the electrolysis of a solution of pure radium chloride, employing a mercury cathode.
  • Marie Curie died of leukemia in Haute Savoie, France, on July 4, 1934; most probably as a result of so much exposure to radiation during her research over the years.
  • On distillation in an atmosphere of hydrogen, this amalgam yielded pure radium.
  • The uses of radium all result from its radiations; the most important of these has been in medicine, principally for the treatment of cancer.
  • Radium has been mixed, in small concentrations, with a paste of zinc sulfide to make a luminescent paint for watch, clock, meter dials, and signs which must be read in the dark.
  • Fluorescent paints activated by ultraviolet radiation are replacing radium paints in airplane panel meters.

Name in other languages:

French: radium

German: Radium

Italian: radio

Spanish: radio


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.