Symbol	Pm	Atomic radius: pm	181	Fusion: kJ/Mole	7.7
Name	Promethium	Ionic radius: pm	(+3)109	Boiling point: °C	3000
Atomic number	61	Electron affinity	-	Melting point: °C	1042
Atomic weight	145.0	1st  ion potential	5.55	Specific Heat Cap: J/(g K)	-
Classification	Trans metal	Natural form	Solid	Thermal Cond: W/(cm K)	0.15
Configuration	[Xe]4f56s2	Crystal structure	Hex	Electrical Cond	-
Oxidation states	3	Density	7.26	Abundance: mg/kg-crust	<0.001
Electronegativity	-	Vaporization: kJ/Mole	-
Proof of the existence of promethium was obtained in 1947 by J.A. Marinsky, L.E. Glendenin, and C.D. Coryell who isolated radioactive isotope promethium-147 from uranium fission products.			Uses - nuclear battery, convert light to electrical current, thickness gauges