terbium, ter′bi-um, n. a rare metal found in certain yttrium minerals.
(c.) Yttria (YO) occurs only in a few rare minerals, and usually in company with terbium and erbium.
Erbium, a rare metal found along with yttrium, terbium, and other rare elements in some rare minerals.
terbium ter·bi·um (tûr'bē-əm)
A soft metallic rare-earth element used in x-ray tubes. Atomic number 65; atomic weight 158.925; melting point 1,359°C; boiling point 3,221°C; specific gravity 8.23; valence 3, 4.
A soft, silvery-gray metallic element of the lanthanide series. It is used in color television tubes, x-ray machines, and lasers. Atomic number 65; atomic weight 158.925; melting point 1,356°C; boiling point 3,123°C; specific gravity 8.229; valence 3, 4. See Periodic Table.