Tellur

52
Te
Gruppe
16
Periode
5
Block
p
Protonen
Elektronen
Neutronen
52
52
76
Generelle Eigenschaften
Ordnungszahl
52
Atommasse
127,6
Massenzahl
128
Kategorie
Halbmetalle
Farbe
Silber
Radioaktiv
Nein
Aus dem Lateinischen tellus (Erde)
Kristallstruktur
Einfach Trigonal
Geschichte
Tellurium was discovered in Transylvania in 1782 by Franz-Joseph Müller von Reichenstein in a mineral containing tellurium and gold.

In 1789, another Hungarian scientist, Pál Kitaibel, also discovered the element independently in an ore from Deutsch-Pilsen which had been regarded as argentiferous molybdenite.

In 1798, it was named by Martin Heinrich Klaproth who earlier isolated it from the mineral calaverite.
Elektronen pro Schale
2, 8, 18, 18, 6
Elektronenkonfiguration
[Kr] 4d10 5s2 5p4
Te
In air, tellurium burns with a greenish-blue flames, forming the dioxide
Physikalische Eigenschaften
Aggregatzustand
Fest
Dichte
6,232 g/cm3
Schmelzpunkt
722,66 K | 449,51 °C | 841,12 °F
Siedepunkt
1261,15 K | 988 °C | 1810,4 °F
Schmelzwärme
17,5 kJ/mol
Verdampfungswärme
48 kJ/mol
Spezifische Wärmekapazität
0,202 J/g·K
Häufigkeit in der Erdkruste
9,9×10-8%
Häufigkeit im Universum
9×10-7%
Metallic
Danksagungen für Bilder: Images-of-elements
Metallic tellurium
CAS-Nummer
13494-80-9
PubChem CID Number
6327182
Atomeigenschaften
Atomradius
140 pm
Kovalenter Radius
138 pm
Elektronegativität
2,1 (Pauling-Skala)
Ionisierungsenergie
9,0096 eV
Molares Volumen
20,5 cm3/mol
Wärmeleitfähigkeit
0,0235 W/cm·K
Oxidationszustände
-2, 2, 4, 5, 6
Anwendung
The primary use of tellurium is in alloys, foremost in steel and copper to improve machinability.

Tellurium is used as a basic ingredient in blasting caps, and is added to cast iron for chill control.

It is used in vulcanizing rubber and in catalysts for petroleum cracking.

Tellurium is used as a coloring agent in ceramics.
Tellurium and tellurium compounds are considered to be mildly toxic
Isotope
Stabile Isotope
120Te, 122Te, 124Te, 125Te, 126Te
Instabile Isotope
105Te, 106Te, 107Te, 108Te, 109Te, 110Te, 111Te, 112Te, 113Te, 114Te, 115Te, 116Te, 117Te, 118Te, 119Te, 121Te, 123Te, 127Te, 128Te, 129Te, 130Te, 131Te, 132Te, 133Te, 134Te, 135Te, 136Te, 137Te, 138Te, 139Te, 140Te, 141Te, 142Te