(So named (
Greek prasios, "leek-green" +
didymium) in
1885 by
C. A. von Welsbach from its
spectroscopic line and from being split from
didymium) A silvery,
malleable chemical element, one of the
rare-earth metals, whose
salts are generally green in color and are used to color
glasses and
enamels.
Symbol: Pr
Atomic number: 59
Atomic weight: 140.90765
Density (at room temperature and pressure): 6.77 g/cc
Melting point: 931°C
Boiling point: 3,520°C
Main valence: +3
Ground state electron configuration: [Xe]4f36s2