Promethium

61
Pm
Gruppe
n/a
Periode
6
Blok
f
Protoner
Elektroner
Neutroner
61
61
84
Generelle Egenskaber
Atomnummer
61
Atommasse
[145]
Masseantal
145
Kategori
Lantanider
Farve
Sølv
Radioaktiv
Ja
Named after the Greek Prometheus, who, according to mythology, stole fire from heaven
Krystalstruktur
n/a
Historie
The existence of an element between neodymium and samarium was first predicted by Czech chemist Bohuslav Brauner in 1902.

Promethium was first produced and characterized at Oak Ridge National Laboratory in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell.

It was produced by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor.
Elektroner i hver skal
2, 8, 18, 23, 8, 2
Elektronkonfiguration
[Xe] 4f5 6s2
Pm
Promethium is the only lanthanide that has no stable isotopes
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
7,26 g/cm3
Smeltepunkt
1315,15 K | 1042 °C | 1907,6 °F
Kogepunkt
3273,15 K | 3000 °C | 5432 °F
Smeltevarme
7,7 kJ/mol
Fordampningsvarme
290 kJ/mol
Varmefylde
-
Forekomst i jordskorpen
n/a
Forekomst i universet
n/a
Pitchblende,
Billede akkrediteringer: Wikimedia Commons (Geomartin)
Pitchblende, a uranium ore and the host for most of Earth's promethium
CAS-nummer
7440-12-2
PubChem CID-nummer
n/a
Atomare egenskaber
Atomradius
183 pm
Kovalent radius
199 pm
Elektronegativitet
-
Ioniseringspotentiale
5,582 eV
Atomvolumen
22,39 cm3/mol
Varmeledningsevne
0,179 W/cm·K
Oxidationstrin
3
Anvendelser
Promethium is also used in atomic batteries for spacecraft and guided missiles.

Promethium is also used to measure the thickness of materials by evaluating the amount of radiation from a promethium source that passes through the sample.

It has possible future uses in portable X-ray sources, and as auxiliary heat or power sources for space probes and satellites.
Promethium is harmful due to its radioactivity
Isotoper
Stabile isotoper
-
Ustabile isotoper
126Pm, 127Pm, 128Pm, 129Pm, 130Pm, 131Pm, 132Pm, 133Pm, 134Pm, 135Pm, 136Pm, 137Pm, 138Pm, 139Pm, 140Pm, 141Pm, 142Pm, 143Pm, 144Pm, 145Pm, 146Pm, 147Pm, 148Pm, 149Pm, 150Pm, 151Pm, 152Pm, 153Pm, 154Pm, 155Pm, 156Pm, 157Pm, 158Pm, 159Pm, 160Pm, 161Pm, 162Pm, 163Pm