Promethium
Name: Promethium
Symbol: Pm
Atomic Number: 61
Mass fraction of the earth’s shell: 1,5 x 10-15 %
Melting Point: 1080 °C
Boiling Point: 3000 °C
Electrical Conductivity: 1,33 x 106 A·V−1·m−1
Name: Promethium
Symbol: Pm
Atomic Number: 61
Mass fraction of the earth’s shell: 1,5 x 10-15 %
Melting Point: 1080 °C
Boiling Point: 3000 °C
Electrical Conductivity: 1,33 x 106 A·V−1·m−1
HISTORY
In 1945, Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell discovered promethium in the USA. It was a fission product of uranium that closed the last gap in the periodic table. Their discovery was not published until 1947.
In naming it, they were inspired by Greek mythology. Everyone knows the Greek titan Prometheus, who – according to legend – brought fire and thus enraged the gods. The name Promethium was seen as a warning shot to all countries that were beginning to arm themselves with nuclear weapons at the time.
CHARACTERISTICS & EXTRACTION
Promethium is the only rare earth that is actually rare. Its natural occurrences on earth are estimated at about 500 to 600 grams. Small amounts are found in the minerals apatite and pitchblende (uraninite). However, it mainly comes from reprocessed fuel rods from nuclear reactors. Each year, significantly less than one kilogramme of promethium is produced and processed.
The silvery-white heavy metal has a pointed target group in industry. One application is promethium-based radionuclide batteries. They serve as drivers for satellites and space probes.
Promethium is also found in hearing aids and pacemakers. Promethium is also used in beta emitters for nuclear measurements or mobile X-ray sources for non-contact measurements. Should humans actually set off for Mars at some point, demand for the rare element could increase.
