Praseodymium

Praseodymium (Pr)

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.
Atomic Number59
Atomic Weight140.90766
Mass Number141
Group
Period6
Blockf
Protons59 p+
Neutrons82 n0
Electrons59 e-
Praseodym 1.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
185 pm
Atomic Volume
Covalent Radius
176 pm
Metallic Radius
Ionic Radius
99 pm
Crystal Radius
112.99999999999999 pm
Van der Waals radius
240 pm
Density
6.773 g/cm³
Boiling Point
3,785 K
Melting Point
1,204 K
Electrons per shell2, 8, 18, 21, 8, 2
Electronegativity
1.13
Electrophilicity
1.1474513688761 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
Heat of Vaporization
331 kJ/mol
Heat of Fusion
11.3 kJ/mol
Heat of Formation
356.9 kJ/mol
Molar Heat Capacity
Specific Heat Capacity
0.193 J/(g⋅K)
Thermal Conductivity
12.5 W/(m K)
Gas Basicity
Dipole Polarizability
216 a₀
C6 Dispersion Coefficient
Oxidation States2, 3, 4
Color
Silver
Crystal StructureSimple Hexagonal (HEX)
Lattice Constant
3.67 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Xe] 4f3 6s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryLanthanides, Lanthanides
CAS Group
IUPAC Group
Glawe Number30
Mendeleev Number17
Pettifor Number31
Geochemical Classrare earth & related
Goldschmidt Classlitophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
9.2 mg/kg
Abundance in Oceans
0.00000064 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe2×10-7%

Isotopes of Praseodymium

Stable Isotopes
141Pr
Unstable Isotopes
121Pr 122Pr 123Pr 124Pr 125Pr 126Pr 127Pr 128Pr 129Pr 130Pr 131Pr 132Pr 133Pr 134Pr 135Pr 136Pr 137Pr 138Pr 139Pr 140Pr 142Pr 143Pr 144Pr 145Pr 146Pr 147Pr 148Pr 149Pr 150Pr 151Pr 152Pr 153Pr 154Pr 155Pr 156Pr 157Pr 158Pr 159Pr

History

Praseodymium was first identified in 1885, in Vienna, by the Austrian chemist Carl Auer von Welsbach. It was discovered in didymium, a substance incorrectly said by Carl Gustav Mosander to be a new element in 1841. Pure metallic praseodymium was first produced in 1931. From the Greek word prasios, green, and didymos, twin

DiscoverersC.F. Aver von Welsbach
Discovery LocationAustria
Discovery Year1885
Name OriginGreek: prasios and didymos (green twin); from its green salts.
Praseodymium is considered to be moderately toxic
Praseodymium is usually stored under a light mineral oil or sealed in glass

Uses

Praseodymium is used as an alloying agent with magnesium to create high-strength metals that are used in aircraft engines. Misch metal, used in making cigarette lighters, contains about 5% praseodymium metal. Praseodymium is used to make specialized yellow glass goggles for glass blowers and welders. 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 Mich metal.

Sources

Obtained from same salts as neodymium.