terbium

A soft, silvery-gray metallic rare-earth element, extracted chiefly from monazite, used in high-temperature fuel cells as a stabilizer and in alloys responsive to a magnetic field. Terbium oxide provides an important phosphor in cathode-ray tubes and low-energy lighting applications. Atomic number 65; atomic weight 158.925; melting point 1,356°C; boiling point 3,230°C; specific gravity 8.230; valence 3, 4. cross-reference: Periodic Table.

A rare element, not yet isolated, occurring in the samarskite of North Carolina and certain other rare minerals, associated with erbium and yttrium.

A rare metallic element, found in certain minerals, as gadolinite and samarskite, with other rare earths such as ytterbium. Symbol Tb. Atomic number 65. Atomic weight 158.925.

a metallic chemical element (symbol Tb) with an atomic number of 65

a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite