praseodymium n 1: a soft yellowish-white trivalent metallic element of the rare earth group; can be recovered from bastnasite or monazite by an ion-exchange process [syn: {praseodymium}, {Pr}, {atomic number 59}]
Praseodymium \Pra`se*o*dym"i*um\, n. [Praseo- + didymium.] (Chem.) An elementary substance, one of the constituents of didymium; -- so called from the green color of its salts. Symbol Ps. Atomic weight 143.6. [1913 Webster]
praseodymium Symbol: Pr Atomic number: 59 Atomic weight: 140.907 Soft silvery metallic element, belongs to the lanthanoids. Only natural isotope is Pr-141 which is not radioactive. Fourteen radioactive isotopes have been artificially produced. Used in rare-earth alloys. Discovered in 1885 by C.A. von Welsbach.