Promethium

Chemical element symbol is (Pm) and atomic number 61.

Promethium is a Rare Earth Metal classified in the group of Light Rare Earth Elements (LREE).

In 1902, Bohuslav Branner speculated that there should be an element in the periodic table between neodymium and samarium. He was not to know that all its isotopes were radioactive and had long disappeared. Attempts were made to discover it and several claims were made, but clearly all were false. However, minute amounts of promethium do occur in uranium ores as result of nuclear fission, but in amounts of less than a microgram per million tonnes of ore.

Promethium is a beta particle emitter; it does not emit gamma radiation. Itis still not well-known properties of the metal Promethium, but two allotropes exist. Promethium salts, for example mixing 147Pm2O and ZnS / Cu 2+, are weakly luminescent in the dark with blue or green glow caused by their high radioactivity.

The element has no other current application as luminescent compounds because of its radioactivity. Its use as source of heat and thus electricity in space applications is currently under study and its use as a potential source for portable X-rays.

Promethium’s longest-lived isotope has a halt-life of only 18 years. For this reason it is not found naturally on Earth. It has been found that a star in the Andromeda galaxy is manufacturing promethium, but it is not known how.