tho·ri·um /ˈθoriəm, ˈθɔr-/
放射性金屬元素,符號Th,原子序90,釷
tho·ri·um /ˈθorɪəm, ˈθɔr-/ 名詞
釷
Tho·ri·um n. 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.
◄ ►
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 [syn: Th,
atomic number 90]
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
neutrons and breeds uranium-233. Discovered by Jons J. Berzelius in
1829.