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 | |