Ordnungszahl: |
61 |
Name: |
Promethium |
Namensursprung: |
Named for the Greek god, Prometheus. |
Entdeckung: |
1945 by J.A. Marinsky, L.E. Glendenin, C.D. Coryell in United States |
Beschreibung: |
Rare earth metal of synthetic origin on the earth, naturally made in stars. |
Vorkommen: |
Does not occur naturally. Found among fission products of uranium, thorium, and plutonium. |
Verwendung: |
It has been used as a source of radioactivity for thickness-measuring gages. |
Gruppe: |
Actinide Metal |
Atomgewicht: |
(144.9127) |
Schmelzpunkt: |
1042 °C |
Siedepunkt: |
3000 °C (estimated) |
Dichte bei 293 K: |
6.475 g/cm³ |
Aggregatszustand bei Raumtemperatur: |
Solid |
Schalen: |
2,8,18,23,8,2 |
Orbitale: |
[Xe] 4f5 6s2 |
Valenzen: |
3 |
1. Ionisierungs- potential: |
5.55 V |
2. Ionisierungs- potential: |
10.903 V |
3. Ionisierungs- potential: |
22.283 V |
Atomradius: |
2.62 Å |
Spezifische Wärme: |
0.18 J/gK |
Verdampfungswärme: |
-- |
Schmelzwärme: |
-- |
Thermischer Ausdehnungskoeffizient: |
-- |
Röntgenemission Energie / Wellenlänge: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
eV |
0 |
0 |
5432.71 |
5961.70 |
0 |
0 |
|
|
|
Å |
0 |
0 |
2.2822 |
2.0797 |
0 |
0 |
|
|
|
|
Röntgenabsorption Energie / Wellenlänge: |
|
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
eV |
45189 |
7428 |
7013 |
6459 |
1647 |
1472 |
1357 |
1052 |
1027 |
Å |
0.27437 |
1.66916 |
1.76794 |
1.91958 |
7.52795 |
8.42292 |
9.13673 |
11.7857 |
12.0726 |
|
Röntgen Fluoreszenz Ausbeute: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
|
92.4% |
0% |
17.1% |
0% |
0% |
0% |
|
|
|
|
Nuklide: |
|
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
Pm143 |
0% |
142.911 |
5/2 |
265y |
EC |
Pm144 |
0% |
144 |
5 |
360y |
EC |
Pm145 |
0% |
144.913 |
5/2 |
17.7y |
EC,α |
Pm146 |
0% |
146 |
3 |
5.53y |
EC,β- |
Pm147 |
0% |
146.915 |
7/2 |
2.62y |
β- |
Pm148 |
0% |
148 |
1 |
5.37d |
β- |
Pm148m |
0% |
148 |
6 |
41.3d |
β-,IT |
Pm149 |
0% |
149 |
7/2 |
2.212d |
β- |
Pm151 |
0% |
151 |
5/2 |
1.183d |
β- | |