Calcium
Calcium (fachsprachlich) oder Kalzium ist ein chemisches Element im Periodensystem der Elemente mit dem Symbol Ca und der Ordnungszahl 20.
Ordnungszahl: |
20 |
Name: |
Calcium |
Namensursprung: |
Latin: calx, calcis (lime). |
Entdeckung: |
1808 by Sir Humphrey Davy in England |
Beschreibung: |
Fairly hard, silvery-white metal. Fifth most abundant element in the earth's crust (41,500 ppm). Occurs only in compounds. |
Vorkommen: |
Obtained from minerals like chalk, limestone and
marble. Pure metal is produced by replacing the calcium in lime
(calcium carbonate, CaCO3) with aluminium in hot, low pressure retorts. |
Verwendung: |
Used by many forms of life to make shells and bones.
Virtually no use for the pure metal, however two of its compounds are,
lime (CaO) and gypsum (CaSO4), are in great demand by a number of industries. |
Gruppe: |
Alkali Earth Metal |
Atomgewicht: |
40.078 |
Schmelzpunkt: |
839°C |
Siedepunkt: |
1484°C |
Dichte bei 293 K: |
1.55 g/cm³ |
Aggregatszustand bei Raumtemperatur: |
Solid |
Schalen: |
2,8,8,2 |
Orbitale: |
[Ar] 4s2 |
Valenzen: |
2 |
1. Ionisierungs- potential: |
6.1132 V |
2. Ionisierungs- potential: |
11.871 V |
3. Ionisierungs- potential: |
50.908 V |
Atomradius: |
2.23 Å |
Spezifische Wärme: |
0.63 J/gK |
Verdampfungswärme: |
153.60 kJ/mol |
Schmelzwärme: |
8.540 kJ/mol |
Thermischer Ausdehnungskoeffizient: |
22.3 10-6 K-1 |
Röntgenemission Energie / Wellenlänge: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
eV |
3690.61 |
4012.86 |
341.276 |
344.979 |
0 |
0 |
|
|
|
Å |
3.35948 |
3.0897 |
36.3299 |
35.94 |
0 |
0 |
|
|
|
|
Röntgenabsorption Energie / Wellenlänge: |
|
K |
L-I |
L-II |
L-III |
M-I |
M-II |
M-III |
M-IV |
M-V |
eV |
4039 |
0 |
352.9 |
349.31 |
0 |
0 |
0 |
0 |
0 |
Å |
3.06971 |
0 |
35.1333 |
35.4944 |
0 |
0 |
0 |
0 |
0 |
|
Röntgen Fluoreszenz Ausbeute: |
|
KA |
KB |
LA |
LB |
MA |
MB |
|
|
|
|
16.3% |
0% |
0.1% |
0% |
0% |
0% |
|
|
|
|
Nuklide: |
|
Anteil |
Gewicht |
Spin |
Halbwertszeit |
Zerfallsmodus |
Ca40 |
96.97% |
39.9626 |
0 |
|
Stable |
Ca41 |
0% |
41 |
7/2 |
1.03E05y |
EC |
Ca42 |
0.64% |
41.9586 |
0 |
|
Stable |
Ca43 |
0.145% |
42.9588 |
7/2 |
|
Stable |
Ca44 |
2.06% |
43.9555 |
0 |
|
Stable |
Ca45 |
0% |
44.956 |
7/2 |
162.7d |
β- |
Ca46 |
0.0033% |
45.9537 |
0 |
|
Stable |
Ca47 |
0% |
46.954 |
7/2 |
4.536d |
β- |
Ca48 |
0.18% |
47.9525 |
0 |
|
Stable |
Ca49 |
0% |
49 |
3/2 |
8.72m |
β- | |