ra·di·um

(rā′dē-əm)

n. Symbol Ra

A rare, brilliant white, luminescent, highly radioactive metallic element found in very small amounts in uranium ores, having more than 40 isotopes and isomers with mass numbers between 201 and 234, of which Ra-226 with a half-life of 1,600 years is the most common. It is used as a neutron source for some research purposes and was formerly widely used in cancer radiotherapy and as a constituent of luminescent paints. Atomic number 88; melting point 696°C; boiling point 1,737°C; specific gravity 5; valence 2. See Periodic Table.

[Latin radius, ray; see ray¹ + -ium.]

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

radium

(ˈreɪdɪəm)

(Elements & Compounds)

a. 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, ²²⁶Ra: 1620 years; valency: 2; relative density: 5; melting pt: 700°C; boiling pt: 1140°C

b. (as modifier): radium needle.

[C20: from Latin radius ray]

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

ra•di•um

(ˈreɪ di əm)

n.

a highly radioactive metallic element whose decay yields radon gas and alpha rays. Symbol: Ra; at. wt.: 226; at. no.: 88.

[< French (1898), = Latin rad(ius) ray (see radius) + -ium -ium²]

ra·di·um

(rā′dē-əm)

Symbol Ra A rare, bright-white, highly radioactive element that is an alkaline-earth metal and gives off its own light. It occurs naturally in very small amounts in ores and minerals containing uranium. Radium is used as a source of radon gas for the treatment of disease and as a neutron source for scientific research. The most common of its several isotopes has a half-life of 1,622 years. Atomic number 88. See Periodic Table.

The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ThesaurusAntonymsRelated WordsSynonymsLegend:

Noun

radium - an intensely radioactive metallic element that occurs in minute amounts in uranium ores

atomic number 88, Ra

metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

uranium ore - any ore from which uranium can be extracted

Translations

راديوم: عُنْصُر فِلِزّي مُشِع

радий

rádium

radium

Radium

radio

raadium

radium

radij

rádium

radíum

radis

rad

radiu

rádium

radium

[ˈreɪdɪəm] N → radio m

Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005

radium

[ˈreɪdiəm] n → radium m

Collins English/French Electronic Resource. © HarperCollins Publishers 2005

radium

n → Radium nt; radium therapy or treatment (Med) → Radiumtherapie f

Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007

radium

[ˈreɪdɪəm] n → radio

Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995

radium

(ˈreidiəm) noun

a radioactive metallic element, used in treating certain diseases.

ra·di·um

L. radium, radio, elemento metálico radioactivo y fluorescente usado en algunas de sus variaciones en el tratamiento de tumores malignos;

___needle → aguja de radio, divisa en forma de aguja que contiene radio usado en radioterapia.

radium

n radio (elemento)

Mentioned in

References in classic literature

Scraps turned around and found a row of girls seated in radium chairs ranged along one wall of the room.

"Perhaps it's the radium, but I rather think it's my splendid intellect."

View in context

`Let the light shine with the intensity of three radium units for fifty tals, and for one xat let it shine with the intensity of one radium unit, and then for twenty-five tals with nine units.' Those were his very words, and to think that wise old Matai Shang should listen to such foolishness."

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The apartment was hewn from the material of the cliff, showing mostly dull gold in the dim light which a single minute radium illuminator in the centre of the roof diffused throughout its great dimensions.

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At his request she sang again as they continued their way along the winding tunnel, which was now lighted by occasional bulbs which appeared to be similar to the radium bulbs with which she was familiar and which were common to all the nations of Barsoom, insofar as she knew, having been perfected at so remote a period that their very origin was lost in antiquity.

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The weight of these rifles is comparatively little, and with the small caliber, explosive, radium projectiles which they use, and the great length of the barrel, they are deadly in the extreme and at ranges which would be unthinkable on Earth.

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Perhaps they would not have gone then had not the band begun to play to announce new arrivals; but before they left the great Throne-Room King Evardo added to Ozma's birthday presents a diadem of diamonds set in radium.

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For, even the preachers have begun to tell us that God is radium, or ether or some scientific compound, and that the worst we wicked ones may expect is a chemical reaction.

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"It is quite simple, being nothing more than a radium generator diffusing radio-activity in all directions to a distance of a hundred yards or so from the flier.

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These labours --the first that were attempted in radiography--served to open the way for Monsieur and Madame Curie to the discovery of radium. It was expected the Professor would shortly read to the Academy of Sciences a sensational paper on his new theory,--the Dissociation of Matter,--a theory destined to overthrow from its base the whole of official science, which based itself on the principle of the Conservation of Energy.

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No subversive radium speculations had shaken his steady scientific faith in the conservation of energy and the indestructibility of matter.

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If a chemist in New York made a new discovery in say radium, all his expenses across the continent were paid, and as well he received a princely fee for his time.

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