Periodic table of the elements
NeodymiumPromethiumSamarium
61
Pm
Promethium
(145)
2
8
18
23
8
2
61
Pm
Promethium
(145)
2
8
18
23
8
2
General
NamePromethium
SymbolPm
Number61
Chemical seriesLanthanides
Group / Period0 / 6
Blockf-block
CAS registry number7440-12-2

Physical properties
Statesolid
Density7.26 g/cm3
Melting point1315 K (1042°C, 1908°F)
Boiling point3273 K (3000 °C, 5432 °F)
Critical point

Atomic properties
Atomic Weight(145) g/mol
Crystal structurehexagonal
Electronegativity1.13
Atomic radius185 pm
Atomic radius (calculated)205 pm
Electron configuration[Xe] 4f5 6s2
Electrons per shell2, 8, 18, 23, 8, 2
Number of protons61
Number of neutrons84

Other languages
SpanishPrometio
PortuguesePromécio
FrenchProméthium
GermanPromethium
ItalianPromezio
RussianПрометий
PolishPromet
Chinese
Arabicبروميثيوم
TurkishPrometyum
DutchPromethium


Periodic table of the elements
NeodymiumPromethiumSamarium