Template:Infobox promethium

Promethium,  ₆₁Pm

General properties
Pronunciation	Template:Infobox element/pronunciation
Appearance	metallic
Standard atomic weight (Ar, standard)	Template:Infobox element/standard atomic weight
Mass number	Template:Infobox element/symbol-to-most-stable-isotope (most stable isotope)
Promethium in the periodic table
Template:Infobox element/periodic table
Atomic number (Z)	61
Group	Template:Infobox element/group
Period	period 6
Block	f-block
Element category	Template:Infobox element/category format
Electron configuration	[Xe] 4f5 6s2
Electrons per shell	2, 8, 18, 23, 8, 2
Physical properties
Phase at STP	solid
Melting point	1315 K ​(1042 °C, ​1908 °F)
Boiling point	3273 K ​(3000 °C, ​5432 °F)
Density (near r.t.)	7.26 g/cm3
Heat of fusion	7.13 kJ/mol
[[Enthalpy of vaporization|Heat of Template:Engvar]]	289 kJ/mol
Atomic properties
Oxidation states	Template:Infobox element/symbol-to-oxidation-state
Electronegativity	Pauling scale: 1.13 (?)
[[Ionization energy|Template:Engvar energies]]	1st: 540 kJ/mol 2nd: 1050 kJ/mol 3rd: 2150 kJ/mol
Atomic radius	empirical: 183 pm
Covalent radius	199 pm
Template:Infobox element/spectral lines
Other properties
Crystal structure	​Template:Infobox element/crystal structure Template:Infobox element/crystal structure
Thermal expansion	9.0 µm/(m·K) (at r.t.)
Thermal conductivity	17.9 W/(m·K)
Electrical resistivity	est. 0.75 µΩ·m (at r.t.)
Magnetic ordering	paramagnetic
Young's modulus	α form: est. 46 GPa
Shear modulus	α form: est. 18 GPa
Bulk modulus	α form: est. 33 GPa
Poisson ratio	α form: est. 0.28
CAS Number	7440-12-2
History
Discovery	Chien Shiung Wu, Emilio Segrè, Hans Bethe (1942)
First isolation	Charles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin, Harold G. Richter (1945)
Named by	Grace Mary Coryell (1945)
Main isotopes of promethium
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