Atomic number:59

Group numbers:3

Period:6

Electronic configuration:[Xe] 4f³ 6s²

Formal oxidation number:+3

Electronegativities:1.13

Atomic radius / pm:182

Relative atomic mass:140.90765 ± 0.00002

 

Praseodymium was discovered by Carl Freiherr Auer von Welsbach (AT) in 1885. The origin of the name comes from the Greek words prasios didymos meaning green twin. It is a silvery white, moderately soft, malleable, ductile metal that reacts slowly with oxygen but reacts rapidly with water. Metal ignites and burns readily. Praseodymium is obtained from same salts as neodymium. It is used with neodymium to make lenses for glass maker's goggles since it filters out the yellow light present in glass blowing. Alloyed with magnesium praseodymium creates a high-strength metal used in aircraft engines. Misch metal, used in the manufacture of pyrophoric alloys for cigarette lighters, contains about 5% praseodymium metal. (Typically composition of misch metal are Ce:Nd:Pr:La:Other rare earth=50:18:6:22:4).

Density / g dm^-3:6773 (293 K)

Molar volume / cm³mol^-1:20.80 (293 K)

Electrical resistivity / μΩcm:68 (20 °C)

Thermal conductivity / W m^-1K^-1:12.5

Melting point / °C:931

Boiling point / °C:3520

Heat of fusion / kJ mol^-1:11.3

Heat of vaporization / kJ mol^-1:357

Heat of atomization / kJ mol^-1:356.69

1st ionization energy / kJ mol^-1:527.20

2nd ionization energy / kJ mol^-1:1017.93

3rd ionization energy / kJ mol^-1:2086.41

in the atmosphere / ppm:-

in the Earth's crust / ppm:3.9

in the oceans / ppm:0.0000002