californium

/kal'euh fawr"nee euhm/, n. Chem.
a transuranic element. Symbol: Cf; at. no.: 98.
[1945-50; named after the University of CALIFORNIA where it was discovered; see -IUM]

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 (Cf),  
 synthetic chemical element of the actinoid series of the periodic table, atomic number 98. Not occurring in nature, californium (as the isotope californium-245) was discovered (1950) by Stanley G. Thompson, Kenneth Street, Jr., Albert Ghiorso, and Glenn T. Seaborg at the University of California, Berkeley, as a product resulting from the helium-ion bombardment of curium-242 (atomic number 96) in the 60-inch cyclotron.

      All californium isotopes are radioactive; the long-lived isotopes are produced from berkelium-249 or from californium-249. They are: californium-249 (360-year half-life); californium-250 (13-year half-life); californium-251 (800-year half-life); and californium-252 (2.65-year half-life). These isotopes have been used in tracer amounts for investigating the chemistry of californium (which exhibits an oxidation state of +3 in acidic aqueous solution) and for preparing microgram quantities of compounds such as the oxychloride CfOCl, the oxide Cf2O3, and the trichloride CfCl3. There is some evidence for a +2 state also. Metallic californium has not yet been prepared.

      Californium-252, because 3 percent of its decay occurs by spontaneous fission, is industrially and medically important as a very intense point source of neutrons. One microgram releases 170,000,000 neutrons per minute.

atomic number
98
stablest isotope
251
oxidation state
+3
electronic config.
[Rn]5f 107s2

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Universalium. 2010.

Look at other dictionaries:

  • Californium — (pronEng|ˌkælɪˈforniəm) is a metallic chemical element with the symbol Cf and atomic number 98. A radioactive transuranic element, californium has very few uses. Uses include starting nuclear reactors (civilian and military); optimizing coal… …   Wikipedia

  • Californium — Berkélium ← Californium → Einsteinium Dy …   Wikipédia en Français

  • CALIFORNIUM — Le californium, élément chimique artificiel de symbole Cf, a été synthétisé pour la première fois en 1950. Son numéro atomique 98 le situe dans la classification périodique parmi les éléments transuraniens, après le curium et le berkélium.… …   Encyclopédie Universelle

  • californium — ☆ californium [kal΄ə fôr′nē əm ] n. [ModL < CALIFORNIA + IUM: so named (1950) by the discoverers, SEABORG Glenn T(heodore) and associates, at the University of California] a radioactive, metallic chemical element, one of the actinides,… …   English World dictionary

  • californium — Symbol: Cf Atomic number: 98 Atomic weight: (249) Radioactive metallic transuranic element. Belongs to actinoid series. Cf 251 has a half life of about 700 years. Nine isotopes are known. Cf 252 is an intense neutron source, which makes it an… …   Elements of periodic system

  • Californium — Eigenschaften …   Deutsch Wikipedia

  • Californium — kalifornis statusas T sritis fizika atitikmenys: angl. californium vok. Californium, n; Kalifornium, n rus. калифорний, m pranc. californium, m …   Fizikos terminų žodynas

  • Californium — Ca|li|fọr|ni|um 〈n.; s; unz.; chem. 〉 künstlich hergestelltes radioaktives chem. Element; oV Kalifornium [nach Kalifornien, Bundesstaat der USA] * * * Ca|li|fọr|ni|um [nach dem amer. Bundesstaat California; ↑ ium (1)], das; s; Symbol: Cf: nur… …   Universal-Lexikon

  • californium — kalifornis statusas T sritis chemija apibrėžtis Cheminis elementas. simbolis( iai) Cf atitikmenys: lot. californium angl. californium rus. калифорний …   Chemijos terminų aiškinamasis žodynas

  • californium — noun Etymology: New Latin, from California, United States Date: 1950 a radioactive element discovered by bombarding curium 242 with alpha particles see element table …   New Collegiate Dictionary

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