Tellurium is one of the rarest elements of the periodic table. It has some interesting characteristics and uses, which will be mentioned in this article. So hang on and get ready to go on a grand tour into the fascinating world of chemistry and its elements.
Discovery and Naming
- The etymology of the name tellurium is as follows: Latin name 'tellus' meaning Earth.
- Tellurium was discovered in a compound form with calaverite by Franz-Joseph Muller von Reichenstein in 1782 in Nagyszeben, Romania.
- Later, in 1798, Martin Heinrich Klaproth successfully isolated it from calaverite.
- He subsequently named it tellurium.
- Tellurium is a very rare element with an occurrence of about 1-5 parts per billion (ppb). This is even lesser than platinum which is 5-37 ppb.
- In fact, it is the rarest element in the solid and stable form.
- Tellurium is seldom found in its pure form. It is usually combined with gold (calaverite, krennerite, petzite, sylvanite) and other metals.
- It is a bright and lustrous, silver colored-element.
- It is brittle.
- Tellurium exhibits metalloid properties, that means it exhibits properties of metals as well as nonmetals.
- It can act as a semi-conductor of electricity.
- Tellurium is commercially obtained as a by-product of a chemical process of refining copper and lead.
- The boiling point of Tellurium is 990ºC.
- It has a melting point of 450ºC.
- It is originally found in the solid form in nature, but a powdered form may also be found.
- When burnt in air, it emits a bluish green flame.
- The chemical symbol of tellurium is Te.
- In the periodic table, it is present in the Groups 13-17.
- It has an atomic number of 52.
- Its atomic mass is 127.6 amu.
- Its atomic volume is 20.5 cm3/mol.
- The number of protons and electrons in a single atom of tellurium is 52.
- The number of neutrons in an atom of tellurium is 76.
- It has a hexagonal crystal structure.
- Its density is 6.24 g/cm3.
- The specific heat capacity of tellurium is 0.20 J g-1K-1.
- Its 3 levels of ionization energy are 869.2 kJ mol-1, 1794.6 kJ mol-1, and 2697.7 kJ mol-1.
- The shell structure of tellurium is as follows - 2,8,18,18,6.
- Tellurium's electronic configuration is [Kr]4d105s25p4.
- Tellurium has a total of 33 isotopes, 5 of which are stable. These are 120Te, 122Te,124Te,125Te, and 126Te.
- Tellurium is mildly toxic, and when exposed to even minute amounts of tellurium, humans can develop tellurium breath (garlic odor) which can take months to go away.
Uses of Tellurium
Now that we have seen some interesting tellurium facts, given below are some of the most common uses of tellurium.
- Tellurium is used to make alloys of stainless steel and lead.
- In the form of bismuth telluride, it is used in thermoelectric devices.
- Since it is a semi-conductor of electricity, it is used in making calculators and computers.
- Tellurium also has uses in the ceramics and stained glass coloring industry.
- Blasting caps for explosives are made from tellurium.
- Vulcanization of rubber and petroleum cracking are processes which use tellurium.
- Tellurium suboxide is also used for making rewritable CDs and DVDs.
- In sulfuric acid, tellurium is used to decrease its corrosive properties.
- It is used to increase the hardness and strength of lead.
- Tellurite agar is used to identify the pathogens responsible for diphtheria.
- Cast iron alloys also use tellurium for chill testing and control.