Tellur

52
Te
Gruppe
16
Periode
5
Blok
p
Protons
Electrons
Neutrons
52
52
76
General Properties
Atomnummer
52
Atommasse
127,6
Mass Number
128
Kategori
Halvmetaller
Farve
Silver
Radioactive
Nej
From the Latin word tellus, earth
Krystalstruktur
Simpel Trigonal
History
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.
Elektroner i hver skal
2, 8, 18, 18, 6
Elektronkonfiguration
[Kr] 4d10 5s2 5p4
Te
In air, tellurium burns with a greenish-blue flames, forming the dioxide
Physical Properties
Tilstandsform
Fast stof
Massefylde
6,232 g/cm3
Smeltepunkt
722,66 K | 449,51 °C | 841,12 °F
Kogepunkt
1261,15 K | 988 °C | 1810,4 °F
Smeltevarme
17,5 kJ/mol
Fordampningsvarme
48 kJ/mol
Varmefylde
0,202 J/g·K
Abundance in Earth's crust
9,9×10-8%
Abundance in Universe
9×10-7%
Metallic
Billede akkrediteringer: Images-of-elements
Metallic tellurium
CAS Number
13494-80-9
PubChem CID Number
6327182
Atomic Properties
Atomradius
140 pm
Kovalent radius
138 pm
Elektronegativitet
2,1 (Paulings skala)
Ionization Potential
9,0096 eV
Atomic Volume
20,5 cm3/mol
Varmeledningsevne
0,0235 W/cm·K
Oxidationstrin
-2, 2, 4, 5, 6
Applications
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
Isotoper
Stable Isotopes
120Te, 122Te, 124Te, 125Te, 126Te
Unstable Isotopes
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