Periodic System for Chemists

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Table
59
140.91

Pr

Praseodymium

Identification

CAS Number: 7440-10-0
Discovery Year: 1885
Discoverer: C.F. Aver von Welsbach
Discovery Location: Austria

Properties

Atomic Mass: 140.90766 →Density: 6.773 g/cm³ →
Crust Abundance: 9.2 mg/kg
Crystal Structure: HEX

Atomic Dimensions

Atomic Radius: 185 pm →
Atomic Radius (Rahm): 286 pm
Covalent Radius: 202.99999999999997 pm →
Van der Waals Radius: 240 pm
Atomic Volume: 20.8 cm³/mol
Lattice Constant: 3.67 Å

Thermodynamics

Melting Point: 1204 K →Boiling Point: 3785 K →Specific Heat: 0.192 J/(g·K) →Thermal Conductivity: 12.5 W/(m·K) →Heat of Fusion: 11.3 kJ/mol →Heat of Vaporization: 331 kJ/mol →
Heat of Formation: 356.9 kJ/mol

Electronic Structure

Electron Config: [Xe] 4f3 6s2
Block: f
Period: 6 →Electronegativity: 1.13 →Electron Affinity: 0.9620000000000001 eV →
Oxidation States: +3, +4

Abundance & Geochemistry

Crust Abundance: 9.2 mg/kg
Sea Abundance: 6.4e-7 mg/L
Geochemical Class: rare earth & related
Goldschmidt Class: litophile

About

Soft silvery metallic element, belongs to the lanthanoids. Only natural isotope is Pr-141 which is not radioactive. Fourteen radioactive isotopes have been artificially produced. Used in rare-earth alloys. Discovered in 1885 by C.A. von Welsbach.

Isotopes

Pr-141 141 100.00%

Related Elements

Category

Lanthanides

Same Period

56 Ba Barium57 La Lanthanum58 Ce Cerium60 Nd Neodymium61 Pm Promethium62 Sm Samarium

Periodic Trends

Electronegativity →Atomic Radius →Density →Melting Point →

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