Promethium
(Pm)
Pm
Category
Lanthanoid
Series
lanthanide
Relative atomic mass
145
Density
7.26
Melting point (°C)
1315
Boiling point (°C)
3203
Electronegativity (Pauling)
1.13
Discovery year
1945
Discovered by
Ernest Marsden and Harry Llewellyn Gregory
created by @lukaswyss
Promethium (Pm) – Element 61