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.

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 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:-

1st ionization energy / kJ mol^-1:869.30

2nd ionization energy / kJ mol^-1:1794.64

3rd ionization energy / kJ mol^-1:2697.75

in the atmosphere / ppm:-

in the Earth's crust / ppm:0.01

in the oceans / ppm:-