metallic rare-earth element, 1879, coined in Modern Latin by Swedish chemist Carl Gustaf Mosander (1797-1858) from Ytterby, name of a town in Sweden where mineral containing it was found.
ytterbium yt·ter·bi·um (ĭ-tûr'bē-əm)
A soft bright allotropic rare-earth element. Atomic number 70; atomic weight 173.04; melting point 824°C; boiling point 1,194°C; specific gravity 6.97 or 6.90 (25°C) depending on allotropic form; valence 2, 3.
A soft, silvery-white metallic element of the lanthanide series that occurs as seven stable isotopes. It is used as a radiation source for portable x-ray machines. Atomic number 70; atomic weight 173.04; melting point 824°C; boiling point 1,196°C; specific gravity 6.972 or 6.54 (25°C) depending on allotropic form; valence 2, 3. See Periodic Table.