Part of the name of this element comes from prasinos, the Greek word for green. Normally a gray color when pure, the element reacts slowly on contact with air to form a green coating. Praseodymium compounds give a yellow color to glass and heat-resistant ceramics, and provide a green color to some artificial jewelry. The praseodymium element also increases the power of magnets containing it.

Summary of properties (Pr)

Atomic weight140.90766(1)
Discoverer (year)Von Welsbach, Baron Auer (1885)
Natural formmetallic solid (hexagonal)
Electron configuration[Xe] 43 6s2
Melting point (ºC)935
Boiling point (ºC)3127
Abundance in earth's crust (ppm)9.2
Isotope (abundance)141Pr (100)
Density g/cm36.77
Van der Waals radius (pm)240
Covalent radius (pm)190
Electronegativity (Pauling)1.13
Vaporization enthalpy (kJ/mol)333.00
Enthalpy of fusion (kJ/mol)6.89
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.10
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.130
Oxidation state+3
Electron affinity (eV)0.96
1st Ionization potential (eV)5.4730

Back to the Periodic Table of the Elements.