|Atomic mass||145 amu|
|Date of discovery||1945|
|Name of discoverer||J.A. Marinsky, L.E. Glendenin and C.D. Coryell|
|Name origin||From Prometheus who stole the fire of the sky and gave it to mankind.|
|Uses||Used in highly specialized miniature batteries.|
|Obtained from||All the promethium originally present when the Earth formed has disappeared due to radioactive decay. Only very small trace amounts are found in uranium ores as a product of nuclear fission.|
Promethium is not known to exist in the earth's crust but a sample was extracted during processing of nuclear reactor fuel waste in 1963. Promethium salts glow in the dark because they are radioactive. Promethium is one of the rare earth elements.