| Ordnungszahl: |
74 |
| Name: |
Tungsten |
| Namensursprung: |
Swedish: tung sten (heavy stone): symbol from its German name wolfram. |
| Entdeckung: |
1783 by Fausto and Juan José de Elhuyar in Spain |
| Beschreibung: |
Hard, steel-gray to white metal. Highest melting point of all metals. |
| Vorkommen: |
Occurs in the minerals scheelite (CaWO4) and wolframite [(Fe,Mn)WO4]. |
| Verwendung: |
Made into filaments for vacuum tubes and electric lights. Also as contact points in cars. Combined with calcium or magnesium it makes phosphors. Tungsten carbide is extremely hard and is used for making cutting tools and abrasives. |
| Gruppe: |
Transition Metal |
| Atomgewicht: |
183.84 |
| Schmelzpunkt: |
3410°C +/-20°C |
| Siedepunkt: |
5660°C |
| Dichte bei 293 K: |
19.3 g/cm³ |
| Aggregatszustand bei Raumtemperatur: |
Solid |
| Schalen: |
2,8,18,32,12,2 |
| Orbitale: |
[Xe] 4f14 5d4 6s2 |
| Valenzen: |
2,3,4,5,6 |
| 1. Ionisierungs- potential: |
7.98 V |
| 2. Ionisierungs- potential: |
-- |
| 3. Ionisierungs- potential: |
-- |
| Atomradius: |
2.02 Å |
| Spezifische Wärme: |
0.13 J/gK |
| Verdampfungswärme: |
824.0 kJ/mol |
| Schmelzwärme: |
35.40 kJ/mol |
| Thermischer Ausdehnungskoeffizient: |
4.5 10-6 K-1 |
| Röntgenemission Energie / Wellenlänge: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| eV |
0 |
0 |
8397.88 |
9672.68 |
1775.53 |
1834.92 |
|
|
|
| Å |
0 |
0 |
1.47639 |
1.28181 |
6.98301 |
6.75699 |
|
|
|
|
| Röntgenabsorption Energie / Wellenlänge: |
| |
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
| eV |
69521 |
12099 |
11543 |
10206 |
2820 |
2575 |
2281 |
1872 |
1810 |
| Å |
0.17834 |
1.02476 |
1.07412 |
1.21483 |
4.39665 |
4.81497 |
5.43557 |
6.62315 |
6.85002 |
|
| Röntgen Fluoreszenz Ausbeute: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| |
95.7% |
0% |
30.4% |
0% |
0% |
0% |
|
|
|
|
| Nuklide: |
| |
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
| W180 |
0.14% |
179.947 |
0 |
|
Stable |
| W181 |
0% |
181 |
9/2 |
121.2d |
EC |
| W182 |
26.41% |
181.948 |
0 |
|
Stable |
| W183 |
14.4% |
182.95 |
1/2 |
|
Stable |
| W184 |
30.64% |
183.951 |
0 |
|
Stable |
| W185 |
0% |
185 |
3/2 |
74.8d |
β- |
| W185m |
0% |
185 |
9/2 |
1.6m |
IT |
| W186 |
28.41% |
185.954 |
0 |
|
Stable |
| W187 |
0% |
187 |
3/2 |
23.9h |
β- |
| W188 |
0% |
188 |
0 |
69.4d |
β- |
|
