radium therapy radiotherapy

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radium
a radioactive metallic chemical element (symbol Ra) with an atomic number of 88
Symbol, Ra; atomic weight, 226
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
Radium was discovered by M
Curie, of Paris, who in 1902 separated compounds of it by a tedious process from pitchblende
The emanation is a heavy gas, the later products are solids
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)
At the same time the light gas helium is formed; it probably consists of the expelled alpha particles
The radioactivity of radium is therefore an atomic property, and is explained as result from a disintegration of the atom
an intensely radioactive metallic element that occurs in minute amounts in uranium ores
Radium, in turn, is believed to be formed indirectly by an immeasurably slow disintegration of uranium
It is possible that lead is the stable end product
It was discovered by Marie Curie and her husband, Pierre Curie, in 1898 and isolated by 1910. All its isotopes are radioactive (see radioactivity). Radium does not occur free in nature but occurs in natural ores such as pitchblende as a disintegration product of radioactive decay of heavier elements, including uranium. Chemically it is highly reactive and has valence 2 in all of its compounds. Its use in medicine (see radiation therapy; radiology; nuclear medicine) has declined because of its cost, and its use in consumer goods (to illuminate watch and clock hands and numbers, as well as instrument dials) was halted because it can cause radiation injury. It is still used for some radiography and as a source of neutrons
Their degree of activity depends on the proportion of radium present, but not on its state of chemical combination or on external conditions
Its compounds color flames carmine and give a characteristic spectrum
An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals
{i} (Ra) radioactive metallic chemical element
These products are regarded as unstable elements, each with an atomic weight a little lower than its predecessor
and Mme
radium therapy radiotherapy
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