Elektronische Daten		Thermische Daten		Sterische Daten
Schalen: 2,8,18,23,8,2 Orbitale: [Xe] 4f5 6s2 Elektronegativität: 1.1, -- 1. Ionization potential: 5.55 eV 2. Ionization potential: 10.903 eV 3. Ionization potential: 22.283 eV Oxidation states: 3 Electrical conductivity: --		Melting point: 1042 °C Boiling point: 3000 °C (estimated) Specific heat: 0.18 J/gK Heat of fusion: -- kJ/mol Heat of vaporization: -- kJ/mol Thermal conductivity: 0.179 W/cmK		Atomic radius: 2.62 Å Ionic radius: 1.09 Å () Covalent radius: 1.63 Å Atomic volume: 22.39 cm³/mol Density (293 K): 6.475 g/cm³ Crystal structure: Hexagonal

Nuklid	Häufigkeit [%]	Masse	Spin	Halbwertszeit	Zerfallsmodus	Zerfallsreihe
143Pm	0	142.911	5/2	265y	EC	View
144Pm	0	144	5	360y	EC	View
145Pm	0	144.913	5/2	17.7y	EC,	View
146Pm	0	146	3	5.53y	EC,-	View
147Pm	0	146.915	7/2	2.62y	-	View
148Pm	0	148	1	5.37d	-	View
148Pmm	0	148	6	41.3d	-,IT	View
149Pm	0	149	7/2	2.212d	-	View
151Pm	0	151	5/2	1.183d	-	View

Legende

Herkunft des Namen:
Beschreibung:	Rare earth metal of synthetic origin on the earth, naturally made in stars.
Entdeckt von:	J.A. Marinsky, L.E. Glendenin, C.D. Coryell
Jahr:	1945
Ort:	USA
Quelle(n):	Does not occur naturally. Found among fission products of uranium, thorium, and plutonium.
Verwendung(en):	It has been used as a source of radioactivity for thickness-measuring gages.