Ordnungszahl: |
77 |
Name: |
Iridium |
Namensursprung: |
Latin: iris (rainbow). |
Entdeckung: |
1804 by S.Tenant, A.F.Fourcory, L.N.Vauquelin, H.V.Collet-Descoltils in England/France |
Beschreibung: |
Heavy, brittle, white metal. |
Vorkommen: |
Found in gravel deposits with platinum. |
Verwendung: |
Used with osmium to tip gold pen points, to make
crucible and special containers. Also to make alloys used for standard
weights and measures, and heat-resistant alloys. Also as hardening
agent for platinum. |
Gruppe: |
Transition Metal |
Atomgewicht: |
192.22 |
Schmelzpunkt: |
2410°C |
Siedepunkt: |
4130°C |
Dichte bei 293 K: |
22.42 g/cm³ |
Aggregatszustand bei Raumtemperatur: |
Solid |
Schalen: |
2,8,18,32,15,2 |
Orbitale: |
[Xe] 4f14 5d7 6s2 |
Valenzen: |
3 |
1. Ionisierungs- potential: |
9.1 V |
2. Ionisierungs- potential: |
-- |
3. Ionisierungs- potential: |
-- |
Atomradius: |
1.87 Å |
Spezifische Wärme: |
0.130 J/gK |
Verdampfungswärme: |
604.0 kJ/mol |
Schmelzwärme: |
26.10 kJ/mol |
Thermischer Ausdehnungskoeffizient: |
6.4 10-6 K-1 |
Röntgenemission Energie / Wellenlänge: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
eV |
0 |
0 |
9175.4 |
10708.6 |
1979.96 |
2053.42 |
|
|
|
Å |
0 |
0 |
1.35128 |
1.15781 |
6.26202 |
6.038 |
|
|
|
|
Röntgenabsorption Energie / Wellenlänge: |
|
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
eV |
76107 |
13418 |
12823 |
11215 |
3174 |
2909 |
2551 |
2116 |
2041 |
Å |
0.16290 |
0.92402 |
|
0.96689 |
|
1.10553 |
3.90628 |
4.26213 |
4.86027 |
|
Röntgen Fluoreszenz Ausbeute: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
|
96.2% |
0% |
33.5% |
0% |
0% |
0% |
|
|
|
|
Nuklide: |
|
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
Ir188 |
0% |
188 |
2 |
1.72d |
EC,β+ |
Ir189 |
0% |
189 |
3/2 |
13.2d |
EC |
Ir190 |
0% |
190 |
4 |
11.8d |
EC |
Ir190m |
0% |
190 |
7 |
1.20h |
IT |
Ir190m2 |
0% |
190 |
11 |
3.20h |
EC,β+,IT |
Ir191 |
37.3% |
190.961 |
3/2 |
|
Stable |
Ir191m |
0% |
191 |
11/2 |
4.93s |
IT |
Ir192 |
0% |
192 |
4 |
73.83d |
β-,EC |
Ir193 |
62.7% |
192.963 |
3/2 |
|
Stable |
Ir193m |
0% |
193 |
11/2 |
10.53d |
IT |
Ir194 |
0% |
194 |
1 |
19.3h |
β- |
Ir194m |
0% |
194 |
11 |
170d |
β- | |