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Praseodymium (Pr)

Praseodymium is a chemical element of the periodic table with chemical symbol Pr and atomic number 59 with an atomic weight of 140.908 u and is classed as lanthanide. Praseodymium is solid at room temperature.

Praseodymium in the periodic table

Atomic number59
AppearanceGrayish white
Color Silver
Number of protons59 p+
Number of neutrons82 n0
Number of electrons59 e-
From Wikipedia, the free encyclopediaPraseodymium is a chemical element with symbol Pr and atomic number 59. Praseodymium is a soft, silvery, malleable and ductile metal in the lanthanide group. It is valued for its magnetic, electrical, chemical, and optical properties.

Physical properties

Phase at STPSolid
Density6.77 g/cm3
Atomic weight140.908 u

Thermal properties

Melting point1208 K
934.85 °C
1714.73 °F
Boiling point3403 K
3129.85 °C
5665.73 °F
Heat of vaporization332.63 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)1.13
Electron affinity93 kJ/mol
Oxidation states0, +1, +2, +3, +4, +5
(a mildly basic oxide)
Ionization energies
  1. 527 kJ/mol
  2. 1020 kJ/mol
  3. 2086 kJ/mol
  4. 3761 kJ/mol
  5. 5551 kJ/mol

Electron configuration for praseodymium

Electron configuration
Shorthand configuration
[Xe] 4f3 6s2
Electron configuration
Full configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f3 5s2 5p6 6s2
Electron configuration chart
Electrons per shell2, 8, 18, 21, 8, 2
Valence electrons 2
Valency electrons 4
Bohr model
PraseodymiumElectron shell for Praseodymium, created by Injosoft ABPr
Figure: Shell diagram of Praseodymium (Pr) atom.
Orbital Diagram

The history of Praseodymium

DiscoveryCarl Auer von Welsbach (1885)
Discovery of praseodymium
In 1841, Swedish chemist Carl Gustav Mosander extracted a rare-earth oxide residue he called didymium from a residue he called "lanthana", in turn separated from cerium salts. In 1885, the Austrian chemist Baron Carl Auer von Welsbach separated didymium into two elements that gave salts of different colours, which he named praseodymium and neodymium. The name praseodymium comes from the Ancient Greek πράσινος (prasinos), meaning 'leek-green', and δίδυμος (didymos) 'twin'.


List of unique identifiers for Praseodymium in various chemical registry databases
CAS Number7440-10-0
ChemSpider ID22384
EC number231-120-3
PubChem CID Number23942