yttrium

yttrium

a silvery metallic element occurring in monazite and gadolinite and used in various alloys, in lasers, and as a catalyst. Symbol: Y; atomic no.: 39; atomic wt.: 88.90585; valency: 3; relative density: 4.469; melting pt.: 1522?C; boiling pt.: 3338?C

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

yttrium

[′i·trē·əm]

(chemistry)

A rare-earth metal, symbol Y, atomic number 39, atomic weight 88.9059; dark-gray, flammable (as powder), soluble in dilute acids and potassium hydroxide solution, and decomposes in water; melts at 1500°C, boils at 2927°C; used in alloys and nuclear technology and as a metal deoxidizer.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Yttrium

 

a chemical element in Group III of the Mendeleev periodic system. Atomic number, 39; atomic weight, 88.9059. One stable isotope, ⁸⁹Y, exists in nature.

Yttrium, scandium, lanthanum, and lanthanides make up the rare earths, a group of elements that are very similar in chemical properties, occurrence in nature, and history of discovery.

Yttrium is a light metal, with a density of 4.472 g/cm³. Theisotope 89Y has a small capture cross section for thermal neu-trons (1.38 ×a 10^-28m², or 1.38 barns), so that the element can be used as a construction material in nuclear engineering. The high durability of relatively light yttrium-aluminum alloys makes them highly suitable for aircraft construction. Yttrium ferrites can be prepared from yttrium oxide, Y₂₀0₃ (of very highpurity); these ferrites are used in radio electronics, hearing aids, and computer memory cells.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.