Plantilya:Infobox praseodymium

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Praseodymium
59Pr
-

Pr

Pa
ceriumpraseodymiumneodymium
Appearance
grayish white
General properties
Name, simbolo, kaiphan praseodymium, Pr, 59
Pronunciation Plantilya:IPAc-en
Plantilya:Respell[1]
Element category puthaw nga lantanido
Group, period, block [[group {{{group}}} element|{{{group}}}]], 6, f
Standard atomic weight 140.90765
Electron configuration [Xe] 4f3 6s2
2, 8, 18, 21, 8, 2
Electron shells of praseodymium (2, 8, 18, 21, 8, 2)
History
Discovery Carl Auer von Welsbach (1885)
Physical properties
Phase magahi
Density (near r.t.) 6.77 g·cm−3
Liquid density at m.p. 6.50 g·cm−3
Melting point 1208 K, 935 °C, 1715 °F
Boiling point 3793 K, 3520 °C, 6368 °F
Heat of fusion 6.89 kJ·mol−1
Heat of vaporization 331 kJ·mol−1
Molar heat capacity 27.20 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1771 1973 (2227) (2571) (3054) (3779)
Atomic properties
Oxidation states 4, 3, 2 (mildly basic oxide)
Electronegativity 1.13 (Pauling scale)
Ionization energies 1st: 527 kJ·mol−1
2nd: 1020 kJ·mol−1
3rd: 2086 kJ·mol−1
Atomic radius 182 pm
Covalent radius 203±7 pm
Miscellanea
Crystal structure hexagonal
Praseodymium has a hexagonal crystal structure
Magnetic ordering paramagnetic[2]
Electrical resistivity (r.t.) (α, poly)
0.700 µΩ·m
Thermal conductivity 12.5 W·m−1·K−1
Thermal expansion (r.t.) (α, poly) 6.7 µm/(m·K)
Speed of sound (thin rod) (20 °C) 2280 m·s−1
Young's modulus (α form) 37.3 GPa
Shear modulus (α form) 14.8 GPa
Bulk modulus (α form) 28.8 GPa
Poisson ratio (α form) 0.281
Vickers hardness 400 MPa
Brinell hardness 481 MPa
CAS registry number 7440-10-0
Most stable isotopes
Main article: Isotopes of praseodymium
iso NA half-life DM DE (MeV) DP
141Pr 100% 141Pr is stable with 82 neutrons
142Pr syn 19.12 h β 2.162 142Nd
ε 0.745 142Ce
143Pr syn 13.57 d β 0.934 143Nd
t  h  u
· r

Plantilya:Template reference list

  1. Plantilya:OED
  2. M. Jackson "Magnetism of Rare Earth" The IRM quarterly col. 10, No. 3, p. 1, 2000