lanthane

Traductions

• anglais

  Date : 1983

  Définition

  An element. State: solid; group: IIIB; atomic no.: 57; atomic 138.9055; Wt:valence: 3; isotopes: 2 stable. The first of the rare-earth metals comprising the lanthanide series of the Periodic Table. It is recovered from monazite sands and the ore bastnasite by action of sulfuric acid. It undergoes considerable surface attack in moist air, and in finely divided from it will catch fire at room temperature, i.e., it is pyrophoric. Lanthanum melts at 920 °C (1668 °F).

  Note :

  It has some application in high-energy fuels and as a reducing agent, but its principal use is in alloys such as misch metal. Lanthanum compounds are used in glass and ceramics, as phosphors in fluorescent lamps, and as analytical reagents.

  Termes :

  1. lanthanum
  2. La

  [La] Symbol for the element lanthenum, the name being derived from a Greek word, meaning « to lie concealed ».