radium
Chemistry. a highly radioactive metallic element whose decay yields radon gas and alpha rays. Symbol: Ra; atomic weight: 226; atomic number: 88.
a lustrous rayon or silk fabric constructed in plain weave and used in women's apparel, lining, and drapery.
Origin of radium
1Words Nearby radium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use radium in a sentence
We know now that radium, or at least radio-active substances, represent the philosopher's stone of the olden time.
Education: How Old The New | James J. Walshradium was discovered in 1898 by M. and Madame Curie and M. Bmont, while experimenting with the uranium mineral pitchblende.
Invention | Bradley A. FiskeIt seems that an atom of radium does actually disintegrate, and by disintegrating give out energy.
Invention | Bradley A. Fiske"They are using radium repellent rays to keep us from approaching," he informed.
The Jameson Satellite | Neil Ronald JonesThe cost of one pound of radium is variously estimated at from one to three millions of dollars.
How to Succeed as an Inventor | Goodwin B. Smith
British Dictionary definitions for radium
/ (ˈreɪdɪəm) /
a highly radioactive luminescent white element of the alkaline earth group of metals. It occurs in pitchblende, carnotite, and other uranium ores, and is used in radiotherapy and in luminous paints. Symbol: Ra; atomic no: 88; half-life of most stable isotope, 226 Ra: 1620 years; valency: 2; relative density: 5; melting pt: 700°C; boiling pt: 1140°C
(as modifier): radium needle
Origin of radium
1Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for radium
[ rā′dē-əm ]
A rare, bright-white, highly radioactive element of the alkaline-earth group. It occurs naturally in very small amounts in ores and minerals containing uranium, and it is naturally luminescent. Radium is used as a source of radon gas for the treatment of disease and as a neutron source for scientific research. Its most stable isotope is Ra 226 with a half-life of 1,622 years. Atomic number 88; melting point 700°C; boiling point 1,737°C; valence 2. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for radium
A naturally occurring radioactive chemical element. Its symbol is Ra.
Notes for radium
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Browse