Promethium
🔋 In Your World
Promethium is one of only two radioactive elements before lead (the other is technetium). Because it has no stable isotopes, it is extremely rare. Its most stable isotope, promethium-147, is used to make long-lasting atomic batteries for spacecraft and missiles. The beta radiation it emits can also be captured by a phosphor to create a steady glow, which is used in luminous paints for signals and watch dials.
📖 The Discovery Story
The existence of element 61 was predicted by Czech chemist Bohuslav Brauner in 1902. After many false claims, it was finally confirmed in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell at Oak Ridge National Laboratory. They found it by analyzing the fission products of uranium fuel from a nuclear reactor. The name "promethium" was suggested by Grace Mary Coryell, wife of one of the discoverers, after Prometheus, the Titan in Greek mythology who stole fire from the gods and gave it to humanity, symbolizing the "harnessing of the fire of the atom."
📊 Properties at a Glance
| Phase at STP | Solid |
| Melting Point | 1042 °C / 1908 °F |
| Boiling Point | 3000 °C / 5432 °F |
| Electron Configuration | [Xe] 4f⁵6s² |
| Abundance in Earth's Crust | Essentially zero |
⚠️ Safety & Handling
All isotopes of promethium are radioactive. It must be handled with specialized equipment and extreme care to protect against radiation exposure. It has no biological role and is hazardous due to the beta radiation it emits, which can damage cells and tissues.