Promethium
61Pm · Prometio · Chebi:33373 · promethium-147 · promethium atom · promethium ISO 9001：2015 REACH
Identifikatoren & physikalische Daten
| CAS No. | 22541-16-8 |
|---|---|
| Summenformel | Pm |
| Durchschnittliche Molmasse | 144,9128 g/mol |
| Monoisotopische Masse | 144,91276 g/mol |
| SMILES | [Pm] |
| InChIKey | VQMWBBYLQSCNPO-UHFFFAOYSA-N |
| PubChem CID | 23944 |
| ChEBI | CHEBI:33373 |
| EC No. | 231-121-9 |
| DTXSID | DTXSID4047755 |
| Lokaler Name | Promethium |
Chemische & physikalische Eigenschaften
| Polarare Oberfläche (TPSA) | 0 |
|---|---|
| H-Brücken-Donoren | 0 |
| H-Brücken-Akzeptoren | 0 |
| Frei drehbare Bindungen | 0 |
| Schwere Atome | 1 |
| Formalladung | 0 |
| Komplexität | 0 |
| Stoffklassen | Physical/Radiation -> Radionuclides |
| SpringerMaterials Properties | electron density of states |
| Physical Description | Solid metal[Merck Index] |
| Schmelzpunkt | 1080° (Weigel) |
| Siedepunkt | 3000°C |
| Dichte | 7.22 |
| Aggregatzustand | silvery metal |
| Farbe | silvery metalhexagonal, hexane |
| Spezifische Wärmekapazität | Cp(gas): 0.17 J/(g·K), at 25℃ |
| EPA chemische Informationen | Promethium (7440-12-2) |
Sicherheit & Vorschriften
| GHS-Einstufung | Not Classified |
|---|---|
| Gefahrenübersicht | All isotopes are radioactive (mass numbers = 132-155)Pm-145 has the longest half-life at 17.7 years, an alpha emitterPresent at low levels in uranium ores[Merck Index] The stable rare earth compounds cause benign and other pneumoconioses, but Promethium is not stable. [Reference #2] Pm-147 with a half-life of 2.6 years is the most useful isotope. Pm-145 has the longest half-lifeit has a specific activity of 940 Ci/g. See Radiation, Ionizing. |
| Hazard Classes and Categories | Not Classified |
| EPA Provisional Peer-Reviewed Toxicity Values | PromethiumPDF DocumentInadequate information to assess carcinogenic potential2007 |
| UN-Transportnummer | 2912 |
| Gefahrenklasse | 7 |
Anwendungen & Verwendung
History
The discovery of this element is credited to J.A. Marinsky and L.E. Glendenin who, in 1945, identified its long-lived isotope Pm-147 (t1/2 2.64 years) in the fission products of uranium. They named the element after Prometheus, who according to Greek mythology stole fire from heaven. The element was first isolated from fission product wastes by G.W. Parker and P.M. Lantz in 1948. It first was recovered from natural sources by O. Erametsa in 1965. An amount less than 0.5 g was recovered from 20 tons of rare earths.Promethium does not occur in metallic form in nature. Minute quantities are associated with other rare earths. It also is detected in uranium fission products. It is probably the rarest of the lanthanide elements.Promethium has very limited applications. It is used in phosphor lights to produce signals. Also, it is used as a beta particle source for thickness gages, nuclear batteries, and portable x-ray units.
Verwenden
Promethium-147 is used in the manufacture of luminescent paint for watch dials, as well as being a source of beta rays.