F. Davies Hyper-Text Untitled Document

Free Web Hosting Provider - Web Hosting - E-commerce - High Speed Internet - Free Web Page

Return to periodic table


H' at. wt. (natural) 1.007967
   at. wt. (H') 1.007822
   at. no. 1
   m.p. - 259.140C
   b.p. - 252.870C 
   density 0.08988 gm./l
   density (liquid) 70.8 gm/i. (-2530C)
   density (solid) 7016 gm/i. (-2620C)
   valence 1.

**Electronic configuration**
K	L	M	N	O	P	Q
1	2	3	4	5	6	7
s	s p	s p d	s p d f	s p d f	s p d f	s p d f
1

DYSPROSIUM (Gr. dysprositos, hard to get at), Dy; at. wt. 162.50; at. no.66; m.p. 14090C; h.p. 23350C; sp. gr. 8.540 (25~C); valence 3. Dysprosium was discovered in 1886 by THE ELEMENlS~Continued) Lecoq de Boisbaudran, but not isolated. Neither the oxide nor the metal was available in relatively pure form until the development of ion-exchange separation and metallographic reduction techniques by Spedding and associates about 1950. Dysprosium occurs along with other so-called rare-earth or lanthanide elements in a variety of minerals, such as xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine. The most important sources, however, are from monazite and basinasite. Dysprosium can be prepared by reduction of the trifluoride with calcium. The element has a metallic, bright silver luster. It is relatively stable in air at room temperature, and is readily attacked and dissolved, with the evolution of hydrogen, by dilute and concentrated mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. Small amounts of impurities can greatly affect its physical properties. While dysprosium has not yet found many applications, its thermal neutron absorption cross- section and high melting point suggest metallurgical uses in nuclear control applications for alloying with special stain- less steels. A dysprosium oxide-nickel cermet has found use in cooling nuclear reactor control rods. This cermet absorbs neutrons readily without swelling or contracting under prolonged neutron bombardment. In combination with vanadium and other rare earths, dysprosium has been used in making laser materials. Dysprosium-cadmium calco- genides, as sources of infrared radiation, have been used for studying chemical reactions. The cost of dysprosium metal has dropped in recent years since the development of ion- exchange and solvent extraction techniques, and the dis- covery of large ore bodies. The metal is still expensive, however, and costs about 70~gm. or $190/gm. in purities of99+ %.

Search For:
Match:	Any word All words Exact phrase Sound-alike matching
Within:
Show:	results summaries
Sort by: