PTL:Promethium
From ChemEd Collaborative
| Symbol: | Pm |
|---|---|
| Atomic Number: | 61 |
| Atomic Weight: | (145) |
| Electron Configuration: | [Xe] 4f5 6s2 |
| Atomic Radius: | 181.0pm |
| Melting Point: | 1042°C |
| Boiling Point: | 3000°C (estimate) |
Promethium is a radioactive metal in the lanthanide series, which stretches from lanthanum (La) through lutetium (Lu).
Contents |
Discovered
The existence of the element was first predicted by Branner in 1902, a prediction confirmed by Moseley in 1914. The element was not found until the early 1940's when it was identified as a product of the irradiation of other rare earth elements.
Name
The name is derived from the god Prometheus who, according to mythology, stole fire from heaven.
Prepared
About 10 g of the metal were isolated in 1963 in the course of reprocessing fuels from nuclear reactors.
Pm does not occur naturally in the earth's crust, although it has been identified on the surface of star HR-465 in Andromeda.
Properties
Promethium is a soft beta emitter, and many of its compounds are luminescent due to radioactivity. Little is known about the properties of metallic promethium.
Uses
Promethium has been suggested for use in [nuclear batteries] in deep space probes. In such a battery beta particles emitted by promethium would excite a phosphor, and a photocell would convert the light produced to electric current.
Due to their luminosity, promethium compounds may also have applications in fluorescent lighting and self-luminous watch dials.
Emission Spectra
This is the emission spectra for Promethium.
