n. Symbol Er
A soft, malleable, silvery element of the lanthanide series, used in metallurgy and nuclear research and to color glass and porcelain. Atomic number 68; atomic weight 167.26; melting point 1,529°C; boiling point 2,868°C; specific gravity 9.066; valence 3. See Periodic Table.
[After Ytterby, a town in Sweden.]
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