radium, Ra, atomic number
(noun) an intensely radioactive metallic element that occurs in minute amounts in uranium ores
Source: WordNet® 3.1
radium (countable and uncountable, plural radiums)
The chemical element (symbol Ra) with an atomic number of 88. It is a soft, shiny and silvery radioactive alkaline earth metal.
(textiles, dated) A type of cloth woven from silk or synthetic yarn, often with a shiny appearance.
radium (third-person singular simple present radiums, present participle radiuming, simple past and past participle radiumed)
(ambitransitive, obsolete) To treat (a tumour, etc.) with radium.
Synonym: radiumize
• marudi
Source: Wiktionary
Ra`di*um, n. [NL., fr. L. radius ray.] (Chem.)
Definition: 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.
Source: Webster’s Unabridged Dictionary 1913 Edition
23 November 2024
(adjective) concerned primarily with theories or hypotheses rather than practical considerations; “theoretical science”
Coffee is a brewed drink prepared from roasted coffee beans, the seeds of berries from certain Coffea species. When coffee berries turn from green to bright red – indicating ripeness – they are picked, processed, and dried. Dried coffee seeds are roasted to varying degrees, depending on the desired flavor.
