• Name: Promethium

  • Symbol: Pm

  • Number of Energy Levels: 6

  • Electrons on the outer energy level: 2

  • Atomic Number: 61

  • Atomic Mass: 145 Amu

  • Protons / Electrons: 61

  • Neutrons: 84

  • Density: 6.475 g/cm3

  • Classification: Rare Earth

Top 13 interesting facts about Promethium

  • Promethium was discovered in 1945 by J.A. Marinsky. Its name derives from the name of the god "Prometheus", who has stolen fire from the sky and gave it to man.
  • Promethium's melting point is at 1315 K (1024 C, 1908 F) and its boiling point is at 3273 K (3000 C, 5432 F).
  • Promethium has similar properties with lanthanides and the neighboring elements neodymium and samarium.
  • Promethium has the third largest atomic radius among lanthanides.
  • Promethium is a very instable chemical element therefore its studies are incomplete.
  • Promethium compounds tend to be pink or reddish in color.
  • Promethium has no stable isotopes and it forms only one stable oxidation state (+3).
  • Promethium can be found in nature as a product of uranium-238 fission.
  • Promethium has been identified in the spectrum of a few stars.
  • Promethium is industrially produced from uranium-235, uranium-238 or neodymium-147.
  • Currently, only Russia produces promethium.
  • Promethium-147 is used in luminous paint, atomic batteries, and to measure the thickness of materials.
  • Promethium has no known biological role.