Promețiu

61
Pm
Grupă
n/a
Perioadă
6
Bloc
f
Protoni
Electroni
Neutroni
61
61
84
Proprietăți Generale
Număr atomic
61
Masă atomică
[145]
Numar de masa
145
Categorie
Lantanide
Culoare
Argint
Radioactive
Da
Din cuvântul grecesc Prometheus, cine fură foc din cer, după mitologia greacă
Structură cristalină
n/a
Istoric
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.
Electroni pe nivelul de energie
2, 8, 18, 23, 8, 2
Configurație electronică
[Xe] 4f5 6s2
Pm
Promethium is the only lanthanide that has no stable isotopes
Proprietăți Fizice
Fază
Solid
Densitate
7,26 g/cm3
Punct de topire
1315,15 K | 1042 °C | 1907,6 °F
Punct de fierbere
3273,15 K | 3000 °C | 5432 °F
Energie de fuziune
7,7 kJ/mol
Energie de evaporare
290 kJ/mol
Căldură specifică
-
Abundența în scoarța Pământului
n/a
Abundența în Univers
n/a
Pitchblende,
Credite imagine: Wikimedia Commons (Geomartin)
Pitchblende, a uranium ore and the host for most of Earth's promethium
CAS Number
7440-12-2
PubChem CID Number
n/a
Proprietăți Atomice
Rază atomică
183 pm
Rază de covalență
199 pm
Electronegativitate
-
Potențial de ionizare
5,582 eV
Volum molar
22,39 cm3/mol
Conductivitate termică
0,179 W/cm·K
Număr de oxidare
3
Aplicații
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
Izotopi
Izotopi stabili
-
Izotopi instabili
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