| Ordnungszahl: |
87 |
| Name: |
Francium |
| Namensursprung: |
Named for France, the nation of its discovery. |
| Entdeckung: |
1939 by Marguerite Derey in France |
| Beschreibung: |
Highly rare and unstable, radioactive metal. |
| Vorkommen: |
Formed by decay of actinium. Chemical properties similar to cesium. Decays to radium or astatine. |
| Verwendung: |
Since its isotopes have such short half-lives there are no commercially significant compounds of francium. |
| Gruppe: |
Alkali Metal |
| Atomgewicht: |
(223.0197) |
| Schmelzpunkt: |
27°C |
| Siedepunkt: |
677°C |
| Dichte bei 293 K: |
-- |
| Aggregatszustand bei Raumtemperatur: |
Solid |
| Schalen: |
2,8,18,32,18,8,1 |
| Orbitale: |
[Rn] 7s1 |
| Valenzen: |
1 |
| 1. Ionisierungs- potential: |
-- |
| 2. Ionisierungs- potential: |
-- |
| 3. Ionisierungs- potential: |
-- |
| Atomradius: |
-- |
| Spezifische Wärme: |
-- |
| Verdampfungswärme: |
-- |
| Schmelzwärme: |
-- |
| Thermischer Ausdehnungskoeffizient: |
-- |
| Röntgenemission Energie / Wellenlänge: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| eV |
0 |
0 |
12031.7 |
14770.7 |
0 |
0 |
|
|
|
| Å |
0 |
0 |
1.03049 |
0.83940 |
0 |
0 |
|
|
|
|
| Röntgenabsorption Energie / Wellenlänge: |
| |
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
| eV |
101130 |
18638 |
17905 |
15030 |
4652 |
4327 |
3663 |
3136 |
3000 |
| Å |
0.1226 |
0.66522 |
0.69246 |
0.82491 |
2.66521 |
2.86539 |
3.3848 |
3.95362 |
4.13285 |
|
| Röntgen Fluoreszenz Ausbeute: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| |
97.2% |
0% |
43.4% |
0% |
0% |
0% |
|
|
|
|
| Nuklide: |
| |
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
| Fr212 |
0% |
211.996 |
5 |
20m |
EC,β+,α |
| Fr221 |
0% |
221.014 |
5/2 |
4.80m |
α |
| Fr223 |
0% |
223.02 |
3/2 |
21.8m |
β-,α |
|
