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Definition of Radium

1. Noun. An intensely radioactive metallic element that occurs in minute amounts in uranium ores.

Definition of Radium

1. n. An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals. Symbol, Ra; atomic weight, 226.4. Radium was discovered by M. and Mme. Curie, of Paris, who in 1902 separated compounds of it by a tedious process from pitchblende. Its compounds color flames carmine and give a characteristic spectrum. It resembles barium chemically. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays (see these terms). By reason of these rays they ionize gases, affect photographic plates, cause sores on the skin, and produce many other striking effects. Their degree of activity depends on the proportion of radium present, but not on its state of chemical combination or on external conditions.The radioactivity of radium is therefore an atomic property, and is explained as result from a disintegration of the atom. This breaking up occurs in at least seven stages; the successive main products have been studied and are called radium emanation or exradio, radium A, radium B, radium C, etc. (The emanation is a heavy gas, the later products are solids.) These products are regarded as unstable elements, each with an atomic weight a little lower than its predecessor. It is possible that lead is the stable end product. At the same time the light gas helium is formed; it probably consists of the expelled alpha particles. The heat effect mentioned above is ascribed to the impacts of these particles. Radium, in turn, is believed to be formed indirectly by an immeasurably slow disintegration of uranium.

Definition of Radium

1. Noun. a radioactive metallic chemical element (''symbol'' Ra) with an atomic number of 88. ¹

¹ Source: wiktionary.com

Definition of Radium

1. a radioactive element [n -S]

Medical Definition of Radium

1. The celebrated radioactive element discovered by Marie and pierre curie in 1898. (12 Dec 1998)

Lexicographical Neighbors of Radium

Literary usage of Radium

Below you will find example usage of this term as found in modern and/or classical literature:

1. The Encyclopedia Americana: A Library of Universal Knowledge (1919)
"The emanations of thorium and radium behave like heavy gases and are ... The emanation of thorium condenses at—120° C., and that from radium at —150° C. ..."

2. Science by American Association for the Advancement of Science (1905)
"Studies of the Effects of radium on Plants and Animals, with Demonstrations: Communicated ... I. Preliminary notes on the effects of radium rays on plants. ..."

3. The Encyclopedia Americana: A Library of Universal Knowledge (1919)
"radium THERAPY. Twenty years after Madame Curie announced the discovery of radium, ... radium came into use as a surgical agent some five years after the ..."

4. Readers' Guide to Periodical Literature by H.W. Wilson Company (1911)
"Inauguration of the most elaborate radium experiment In the world. Cur. Lit. 51: 395. ... International radium standard; how it is to b* derived. Sei. ..."

5. Smithsonian Physical Tables by Smithsonian Institution, Frederick Eugene Fowle (1916)
"radium Emanation. Carle. At the Radiology Congress in Brussels in 1910, it was decided to call the amount of emanation | in equilibrium with I gram of pure ..."

6. The Medical Clinics of North America by Michael C. Fiore, Stephen S. Entman, Charles B. Rush (1920)
"Because of this fact he used radium irradiations, for the first time in 1911, ... At first radium was applied through the urethra because its anatomic ..."

7. Standard Methods of Chemical Analysis: A Manual of Analytical Methods and by Wilfred Welday Scott (1922)
"Uranium decomposes in succession into the following products: Uranium Xi, Uranium X«, Uranium II, Ionium, radium, Emanation, radium A, radium B, radium C, ..."

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