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Praseodymium

Metalsolid
Symbol: Pr
Atomic number: 59
Atomic mass: 140.90765
Group: Lanthanide
CAS-number: 7440-10-0

Physical data
Isotopes
Other info
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Physical data

Electronic data

Shells: 2, 8, 18, 21, 8, 2
Orbitals: [Xe] 4f3 6s2
Electronegativity: --, 1.1
1. Ionization potential: 5.464 eV
2. Ionization potential: 10.551 eV
3. Ionization potential: 21.62 eV
Oxidation states: 4, 3
Electrical conductivity: 0.0148 10^6

Thermal data

Melting point: 931 °C
Boiling point: 3520 °C
Specific heat: 0.19 J/gK
Heat of fusion: 6.890 kJ/mol
Heat of vaporization: 296.80 kJ/mol
Thermal conductivity: 0.125 W/cmK

Steric data

Atomic radius: 2.67 Å
Ionic radius: 1.13 Å (+3)
Covalent radius: 1.65 Å
Atomic volume: 20.8 cm³/mol
Density (293 K): 6.77 g/cm³
Crystal structure: hexagonal
hexagonal

Isotopes

NuclideAbundance [%]MassSpinHalflifeDecay modeDecay tree
141Pr 100 140.908 5/2 -- --
142Pr 0 142 2 19.12h β-, EC View
143Pr 0 143 7/2 13.57d β- View
144Pr 0 144 0 17.28m β- View
144Prm 0 144 3 7.2m IT, β- View

Other info

Name origin:Greek: prasios and didymos (green twin); from its green salts.
Description:Silvery white, moderately soft, malleable, ductile metal.
Discovered by:C.F. Aver von Welsbach
Year:1885
Place:Austria
Sources:Obtained from same salts as neodymium.
Use(s):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 creates a high-strength metal used in aircraft engines. Makes up 5% of Mischmetal.