Symbol Pr Atomic radius: pm 182 Fusion: kJ/Mole 6.89
Name Praseodymium Ionic radius: pm (+3)113 Boiling point: C 3520
Atomic number 59 Electron affinity - Melting point: C 931
Atomic weight 140.9 1st  ion potential 5.46 Specific Heat Cap: J/(g K) 0.19
Classification Trans metal Natural form Solid Thermal Cond: W/(cm K) 0.13
Configuration [Xe]4f36s2 Crystal structure Hex Electrical Cond 0.0148
Oxidation states 3,4 Density 6.77 Abundance: mg/kg-crust 9.2
Electronegativity 1.13 Vaporization: kJ/Mole 333.0    
Praseodymium was discovered in didymia, a mixture of several rare-earth oxides.  From it, Carl Auer von Welsbach separated salts of the elements praseodymium and neodymium in 1885. Uses - alloys, welder's masks, coloring galss and ceramics, core material for carbon arc lights used by motion picture industry