資料來源 : pyDict

放射性金屬元素,符號Th,原子序90,釷

資料來源 : Webster's Revised Unabridged Dictionary (1913)

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.

資料來源 : WordNet®

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}]