1. Because of its instability, chemical studies of promethium are incomplete. 2. Other radioactive elements discovered in this star include technetium and promethium . 3. This same shot ignited his Promethium tanks, immolating the surrounding area. 4. The element promethium also draws its name from Greek mythology, 5. Thus it is the only promethium isotope with an experimentally observed alpha decay. 6. After creating a vacuum, the chemicals were mixed to produce promethium metal: 7. In 1963, promethium ( III ) fluoride was used to make promethium metal. 8. In 1963, promethium ( III ) fluoride was used to make promethium metal. 9. Uranium is thus " responsible " for 560 g promethium in Earth's crust. 10. Currently, Russia is the only country producing promethium -147 on a relatively large scale.