Chemical Elements History and Information Promethium

About the chemical element Promethium, its symbol, atomic number and weight, who discovered it and when.

The Atomic Elements and Their Uses

(Element) (Symbol) (Atomic number) (Atomic weight)

Promethium Pm 61 (145)

Discovered by Jacob Marinsky and Lawrence Glendenin of the U.S. in 1947. Promethium is the source of energy for a luminescent watch dial. Its weak and therefore harmless radiation is sufficient to excite zinc sulfide mixed into the paint with the promethium. Particles of zinc sulfide emit a green light when struck by promethium's radiation.