| Ordnungszahl: |
5 |
| Name: |
Boron |
| Namensursprung: |
From Arabic and Persian words for borax. |
| Entdeckung: |
1808 by Sir H. Davy, J.L. Gay-Lussac, L.J. Thénard in England/France |
| Beschreibung: |
Hard, brittle, lustrous black semimetal. Exists in the earth's crust at an average proportion of about 10 parts per million. |
| Vorkommen: |
Obtained from kernite, a kind of borax (Na2B4O7·10H2O). High purity boron is produced by electrolysis of molten potassium fluroborate and potassium chloride (KCl). |
| Verwendung: |
Used with titanium and tungsten to make heat resistant alloys for jets and rockets. |
| Gruppe: |
Non-Metal |
| Atomgewicht: |
10.811 |
| Schmelzpunkt: |
2079°C |
| Siedepunkt: |
4000°C |
| Dichte bei 293 K: |
2.34 g/cm³ |
| Aggregatszustand bei Raumtemperatur: |
Solid |
| Schalen: |
2,3 |
| Orbitale: |
[He] 2s2 2p1 |
| Valenzen: |
3 |
| 1. Ionisierungs- potential: |
8.2980 V |
| 2. Ionisierungs- potential: |
25.154 V |
| 3. Ionisierungs- potential: |
37.93 V |
| Atomradius: |
1.17 Å |
| Spezifische Wärme: |
1.02 J/gK |
| Verdampfungswärme: |
489.70 kJ/mol |
| Schmelzwärme: |
50.20 kJ/mol |
| Thermischer Ausdehnungskoeffizient: |
4.7 10-6 K-1 |
| Röntgenemission Energie / Wellenlänge: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| eV |
183.410 |
0 |
0 |
0 |
0 |
0 |
|
|
|
| Å |
67.6001 |
0 |
0 |
0 |
0 |
0 |
|
|
|
|
| Röntgenabsorption Energie / Wellenlänge: |
| |
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
| eV |
188 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
| Å |
65.9497 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
| Röntgen Fluoreszenz Ausbeute: |
| |
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
| |
0.1% |
0% |
0% |
0% |
0% |
0% |
|
|
|
|
| Nuklide: |
| |
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
| B10 |
19.7% |
10.0129 |
3 |
|
Stable |
| B11 |
80.3% |
11.0093 |
3/2 |
|
Stable |
|
