About

Praseodymium is a soft, silvery rare-earth metal, named 'green twin' because of the color of its salt. It is used with neodymium to create high-strength magnets used in electric motors and wind turbines. Its compounds produce a characteristic yellow-green color in glass and ceramics, and this glass is used to make welder's and glassblower's goggles as it blocks infrared radiation.

Atomic Properties

Atomic Number59

Atomic Weight140.908 u

Neutrons (common)82

Electron Configuration[Xe] 4f³ 6s²

Full Configuration1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f³ 5s² 5p⁶ 6s²

Electrons per Shell2, 8, 18, 21, 8, 2

Electronegativity1.13

Electron Affinity11.8 kJ/mol

Oxidation States+4, +3

Covalent Radius182 pm

Ionic Radius99 pm

Periodic Table Position

Group3

Period6

BlockF

Chemical SeriesLanthanoids

Physical Properties

State at STPsolid

Appearancesilvery-white, yellowish tinge

Crystal Structurehcp

Magnetic Orderingparamagnetic

Speed of Sound2,280 m/s

Poisson Ratio0.281

Thermal Properties

Melting Point1,208 K

Boiling Point3,793 K

Thermal Expansion0 1/K

Thermal Conductivity12.5 W/(m·K)

Specific Heat0.193 J/(g·K)

Molar Heat27.2 J/(mol·K)

Heat of Fusion6.89 kJ/mol

Heat of Vaporization331 kJ/mol

Abundance

In Earth's Crust9.2 ppm

In Ocean0 ppm

In Solar System0.001 ppm

In Universe0.002 ppm

Discovery

Discovered byCarl Auer von Welsbach

Discovery Year1,885

Occurrenceprimordial

CAS Number7440-10-0

Electron Configuration

Energy

↿⇂

↿

Isotopes of Praseodymium

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
¹⁴¹Pr	140.907650	100%	Stable	Stable

Interactive Visualization

Explore the 3D Bohr model of Praseodymium in our interactive viewer.

View 3D Model of Praseodymium