Dysprosium

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Dysprosium \Dys*pro"si*um\, n. [NL., fr. Gr. dyspro`sitos hard
     to get at.] (Chem.)
     An element of the rare earth-group. Symbol Dy; at. wt.,
     162.5.
     [Webster 1913 Suppl.]



From WordNet (r) 2.0 [wn]:

  dysprosium
       n : a trivalent metallic element of the rare earth group; forms
           compounds that are highly magnetic [syn: {Dy}, {atomic
           number 66}]

From Elements database 20001107 [elements]:

  dysprosium
  Symbol: Dy
  Atomic number: 66
  Atomic weight: 162.50
  Metallic with a bright silvery-white lustre. Dysprosium belongs to the
  lanthanoids. It is relatively stable in air at room temperatures, it will
  however dissolve in mineral acids, evolving hydrogen. It is found in
  from rare-earth minerals. There are seven natural isotopes of dysprosium,
  and eight radioisotopes, Dy-154 being the most stable with a half-life of
  3*10^6 years. Dysprosium is used as a neutron absorber in nuclear fission
  reactions, and in compact disks. It was discovered by Paul Emile Lecoq de
  Boisbaudran in 1886 in France. Its name comes from the Greek word
  dysprositos, which means hard to obtain.