Definition of radium in English:

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Pronunciation: /ˈreɪdɪəm/


[mass noun]
The chemical element of atomic number 88, a rare radioactive metal of the alkaline earth series. It was formerly used as a source of radiation for radiotherapy. (Symbol: Ra)
Example sentences
  • Rutherford was studying the structure of matter by bombarding a very thin gold foil with the alpha radiation from radium and polonium.
  • All isotopes of radium are radioactive with radium - 226 being the most stable.
  • The ability of radioactive substances such as radium to radiate energy, apparently spontaneously and continuously, appeared to contradict the law of the conservation of energy.


Late 19th century: from Latin radius 'ray' + -ium.

Words that rhyme with radium

palladium, stadium, vanadium

For editors and proofreaders

Line breaks: ra¦dium

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