Pm
Promethium
Lanthanide
Promethium is a rare earth element that is radioactive and does not occur naturally in significant quantities.
Key Facts
Atomic Number
61
Atomic Weight
145
State
Solid
Half-life
17.7 years (Pm-145)
Discovered
1945
Jacob A. Marinsky, Lawrence E. Glendenin, Charles D. Coryell
Overview
Description
Promethium is a rare earth element that is radioactive and does not occur naturally in significant quantities.
Discovery
Promethium was discovered in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin, Charles D. Coryell.