A shiny, gray metallic element of the lanthanide series. It is ductile and malleable and is used in electronic components, alloys, and lighter flints. It is also used in glass polishing, as a catalyst in self-cleaning ovens, and in various nuclear applications. Atomic number 58; atomic weight 140.12; melting point 795°C; boiling point 3,468°C; specific gravity 6.67 to 8.23; valence 3, 4. See
Periodic Table.