- Made In USA
- 2x2x2 inches
- Radioactive symbol. No sample.
Promethium's atomic number is 61and its symbol is Pm. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in Earth's crust at any given time.
The discoverers proposed the name "prometheum" (the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans, to symbolize "both the daring and the possible misuse of mankind's intellect". However, a sample of the metal was made only in 1963.
Practical applications exist only for chemical compounds of promethium-147, which are used in luminous paint, atomic batteries and thickness-measurement devices.
This display is contained within crystal clear lucite acrylic.