yttrium

A silvery metallic element, not a rare earth but occurring in nearly all rare-earth minerals, used in various metallurgical applications, notably to increase the strength of magnesium and aluminum alloys. Its oxide and other compounds are useful as phosphors, microwave filters, laser dopants, and superconducting materials. Atomic number 39; atomic weight 88.906; melting point 1,522°C; boiling point 3,345°C; specific gravity 4.469 (at 25°C); valence 3. cross-reference: Periodic Table.

Chemical symbol, Y; atomic weight, 89 (?). A metal, the base of the earth yttria.

A rare metallic element of the boron-aluminium group, found in gadolinite and other rare minerals, and extracted as a dark gray powder. Symbol Y. Atomic number 39. Atomic weight, 88.9.

A metallic chemical element (symbol Y) with an atomic number of 39.

a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys