r`ēəm), artificially produced radioactive chemical element; symbol Cm; at. no. 96; mass no. of most stable isotope 247; m.p. about 1,340°C;; b.p. 3,110°C;; sp. gr. 13.5 (calculated); valence +3, +4. A hard, brittle, silvery metal that tarnishes in air, curium is chemically reactive and resembles gadolinium in its chemical properties, although it has a more complex crystalline structure. Oxides, fluorides, a chloride, a bromide, and an iodide of curium have been prepared. Curium is a member of the actinide series actinide series, a series of radioactive metallic elements in Group 3 of the periodic table . Members of the series are often called actinides, although actinium (at. no. 89) is not always considered a member of the series...... Click the link for more information. in Group 3 of the periodic table periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley . In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the
..... Click the link for more information. . Sixteen isotopes of curium are known. Curium-242, prepared by neutron bombardment of americium-241, has a half-life half-life, measure of the average lifetime of a radioactive substance (see radioactivity ) or an unstable subatomic particle. One half-life is the time required for one half of any given quantity of the substance to decay.
..... Click the link for more information. of 163 days; curium-247, the most stable isotope, has a half-life of 15.6 million years. Some curium isotopes are available in multigram quantities.
Curium is intensely radioactive; it is about 3,000 times as radioactive as radium radium (rā`dēəm) [Lat. radius=ray], radioactive metallic chemical element; symbol Ra; at. no. 88; at. wt. 226.0254; m.p.
..... Click the link for more information. . It is also very toxic when absorbed into the body because it accumulates in the bones and disrupts the formation of red blood cells. Curium-242 and curium-244 are used in the space program as a heat source (from the heat they generate as they undergo radioactive decay) for compact thermionic and thermoelectric power generation.
Curium has not been found to occur naturally; it was the third transuranium element transuranium elements, in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ.
..... Click the link for more information. to be synthesized. Curium was first produced by the bombardment of plutonium-239 with alpha particles in a cyclotron at the Univ. of California at Berkeley. Identified in 1944 by Glenn T. Seaborg Seaborg, Glenn Theodore (sē`bôrg), 1912–99, American chemist, b. Ishpeming, Mich., grad. Univ.
..... Click the link for more information. , Ralph A. James, and Albert Ghiorso, it was named for Pierre and Marie Curie Pierre Curie, 1859–1906, scientist, and his wife,
Marie Sklodowska Curie, 1867–1934, chemist and physicist, b. Warsaw, are known for their work on radioactivity and on radium.
..... Click the link for more information. , the noted pioneers in the study of radioactivity. The metal was first isolated in visible amounts as the hydroxide by L. B. Werner and I. Perlman in 1947.
curium
curium [′kyu̇r·ē·əm]
How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content.
| ?Page tools | ||
|---|---|---|
|