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As
33
Se
34
Br
35
Sb
51
Te
52
I
53
Bi
83
Po
84
At
85

 

Periodic table

de  German

Tellur

en  English

Tellurium

fr  French

Tellure

hr  Croatian

Telurij

it  Italian

Tellurio

es  Spanish

Teluro

 

Te
Te
Tellurium

PERIODIC TABLE OF THE ELEMENTS

TELLURIUM

CHALCOGENS ELEMENT

 

Atomic number:52

Group numbers:16

Period:5

Electronic configuration:[Kr] 4d10 5s2 5p4

Formal oxidation number:-2 +4 +6

Electronegativities:2.1

Atomic radius / pm:143.2

Relative atomic mass:127.60 ± 0.03

 

Tellurium was discovered by Franz Joseph Muller von Reichstein (AT) in 1782. The origin of the name comes from the Latin word tellus meaning earth. It is a silvery-white, brittle semi-metal that is unreactive with water or HCl, burns in air or oxygen and dissolves in HNO3. Tellurium is obtained as a by-product of copper and lead refining. It is used to improve the machining quality of copper and stainless steel products and to colour glass and ceramics. It is also used in thermoelectric devices, in the rubber industry and it is a basic ingredient in manufacturing blasting caps.

PHYSICAL PROPERTIES

Density / g dm-3:6240 (293 K)

 5797 (m.p.)

Molar volume / cm3mol-1:20.45 (293 K)

 22.01 (m.p.)

Electrical resistivity / μΩcm:436000 (20 °C)

THERMAL PROPERTIES

Thermal conductivity / W m-1K-1:2.35

Melting point / °C:449.51

Boiling point / °C:988

Heat of fusion / kJ mol-1:13.5

Heat of vaporization / kJ mol-1:104.6

Heat of atomization / kJ mol-1:-

IONIZATION ENERGIES

First ionization energy / kJ mol-1:869.30

Second ionization energy / kJ mol-1:1794.64

Third ionization energy / kJ mol-1:2697.75

ABUNDANCE OF ELEMENTS

in the atmosphere / ppm:-

in the Earth's crust / ppm:0.01

in the oceans / ppm:-

CRYSTALLOGRAPHIC DATA

hexagonal

Crystal structure:

hexagonal

Unit-cell dimensions / pm:

a=445.65, c=592.68

Space group:

P3121

ISOTOPES

IsotopeRelative atomic massMass percent (%)
120Te119.90402(1)0.096(2)
122Te121.903047(2)2.603(4)
123Te122.904273(2)0.908(2)
124Te123.902819(2)4.816(6)
125Te124.904425(2)7.139(6)
126Te125.903306(2)18.95(1)
128Te127.904461(2)31.69(1)
130Te129.906223(2)33.80(1)

REDUCTION POTENTIALS

Balanced half-reaction Eo / V
Te4+ + 4e- = Te(s)+0.568
Te4+ + 2H+ + 6e- = H2Te(g)+0.132
TeO42- + 4H+ + 2e- = TeO2(s) + 2H2O+1.509
HTeO4- + 3H+ + 2e- = TeO2(s) + 2H2O+1.202
H2TeO4 + 2H+ + 2e- = TeO2(s) + 2H2O+1.020
TeO42- + 2H+ + 2e- = TeO32- + H2O+0.892
HTeO4- + H+ + 2e- = TeO32- + H2O+0.584
HTeO4- + 2H+ + 2e- = HTeO3- + H2O+0.813
H2TeO4 + H+ + 2e- = HTeO3- + H2O+0.631
H2TeO4 + 3H+ + 2e- = HTeO2+ + 2H2O+0.953
H2TeO4 + 6H+ + 2e- = Te4+ + 4H2O+0.920
Te(OH)6(s) + 2H+ + 2e- = TeO2(s) + 4H2O+1.02
TeO32- + 6H+ + 4e- = Te(s) + 3H2O+0.827
HTeO3- + 5H+ + 4e- = Te(s) + 3H2O+0.713
HTeO2+ + 3H+ + 4e- = Te(s) + 2H2O+0.551
TeO2+ + 5H+ + 6e- = H2Te(g) + 2H2O+0.121
Te(s) + 2H+ + 2e- = H2Te(g)- 0.739
Te(s) + 2e- = Te2-- 1.14

 

51 Antimony <=
52 Tellurium
=> 53 Iodine