thorium : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)

English Dictionary: thorium	by the DICT Development Group
3 results for thorium
From WordNet (r) 3.0 (2006) [wn]:
thorium n a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands Synonym(s): thorium, Th, atomic number 90
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Thorium \Tho"ri*um\, n. [NL. See {Thorite}.] (Chem.) A metallic element found in certain rare minerals, as thorite, pyrochlore, monazite, etc., and isolated as an infusible gray metallic powder which burns in the air and forms thoria; -- formerly called also {thorinum}. Symbol Th. Atomic weight 232.0.
From The Elements (22Oct97) [elements]:
thorium Symbol: Th Atomic number: 90 Atomic weight: 232.038 Grey radioactive metallic element. Belongs to actinoids. Found in monazite sand in Brazil, India and the US. Thorium-232 has a half-life of 1.39x10^10 years. Can be used as a nuclear fuel for breeder reactors. Thorium-232 captures slow {neutron}s and breeds uranium-233. Discovered by Jons J. Berzelius in 1829.