Ytterbium

from WordNet (r) 3.0 (2006)

ytterbium
    n 1: a soft silvery metallic element; a rare earth of the
         lanthanide series; it occurs in gadolinite and monazite and
         xenotime [syn: {ytterbium}, {Yb}, {atomic number 70}]

from The Collaborative International Dictionary of English v.0.48

Ytterbium \Yt*ter"bi*um\, n. [NL., fr. Ytterby, in Sweden. See
   {Erbium}.] (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}.
   [1913 Webster]

   Note: Ytterbium is associated with other rare elements, and
         probably has not been prepared in a pure state.
         [1913 Webster]

from The Elements (07Nov00)

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.

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