A metallic element of the rare-earth group, discovered spectroscopically by Demarcay in 1896. Symbol, Eu; at. wt., 152.0.
- A silvery-white, soft, rare-earth element occurring in monazite and bastnaesite and used to dope lasers and to absorb neutrons in research. Atomic number 63; atomic weight 151.96; melting point 826°C; boiling point 1,439°C; specific gravity 5.259; valence 2, 3. See Table at element.