yt·ter·bi·um /ɪˈtɝbiəm/
  鐿
  yt·ter·bi·um /ɪˈtɝbɪəm/ 名詞
  Yt·ter·bi·um n.  Chem. A rare element of the boron group, sometimes associated with yttrium or other related elements, as in euxenite and gadolinite. Symbol Yb; provisional atomic weight 173.2.  Cf. Yttrium.
  Note: ☞ Ytterbium is associated with other rare elements, and probably has not been prepared in a pure state.
  ◄ ►
  ytterbium
       n : a soft silvery metallic element; a rare earth of the
           lanthanide series; it occurs in gadolinite and monazite
           and xenotime [syn: Yb, atomic number 70]
  ytterbium
  Symbol: Yb
  Atomic number: 70
  Atomic weight: 173.04
  Silvery metallic element of the lanthanoids. Seven natural isotopes and
  ten artificial isotopes are known.  Used in certain steels. Discovered by
  J.D.G. Marignac in 1878.