- Related Topics:
- chemical element
- oxygen group element
tellurium
-
What is tellurium?
Tellurium (Te) is a silvery-white, semimetallic chemical element in the oxygen group (Group 16 [VIa] of the periodic table). It has properties intermediate between those of metals and nonmetals and is closely allied with selenium in chemical and physical traits.
Tellurium was first isolated in 1782 by Franz Joseph MĂŒller von Reichenstein, and its elemental nature was confirmed in 1798 by Martin Heinrich Klaproth, who named it after Earth (Tellus).
It is a poor conductor of heat and only a fair conductor of electricity. Tellurium burns in air or oxygen with a blue-green flame, forming tellurium dioxide ((TeO_2)).
Tellurium is used to increase the ductility of aluminum alloys, the hardness and tensile strength of tin alloys, and the machinability of stainless steel and copper.
Properties of tellurium:
* Atomic number: 52
* Atomic weight: 127.60
* Melting point: 449.8 °C (841.6 °F)
* Boiling point: 989.9 °C (1,813.8 °F)1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Where can tellurium be found naturally?
Tellurium, a semimetallic chemical element, is not often found uncombined but rather as compounds of metals like copper, lead, silver, or gold. It is obtained as a by-product of refining copper or lead. Tellurium and selenium are found together in many ores. To isolate them, solutions containing salts of both selenious and tellurous acids (H2SeO3 and H2TeO3) are treated with sulfuric acid, causing tellurium dioxide (TeO2) to separate due to its low solubility, while the selenious acid remains dissolved. Japan, the United States, and Canada are the worldâs largest producers of tellurium.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What does tellurium look like?
Tellurium is a silvery white element with properties that are intermediate between metals and nonmetals. It is a brittle element that crystallizes in rhombohedral form, and its crystal structure is very similar to that of gray selenium. Tellurium atoms form spiral chains in the crystal with a TeâTe distance of 3.74 Ă .
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are some properties of tellurium?
Tellurium (Te) is a semimetallic chemical element in the oxygen group with chemical and physical properties similar to selenium. It is a silvery white, brittle element and a fair conductor of electricity.
Properties of tellurium:
* Atomic Number: 52
* Atomic Weight: 127.60
* Melting Point: 449.8 °C
* Boiling Point: 989.9 °C
* Oxidation States: â2, +2, +4, +6Tellurium burns in air with a blue-green flame, forming tellurium dioxide (TeO2). It is unaffected by hydrochloric acid, but nitric acid or aqua regia oxidizes it to tellurous acid (H2TeO3). Tellurium reacts with halogens to form halides and combines with most metals at elevated temperatures to form tellurides. Japan, the United States, and Canada are the worldâs largest producers of tellurium.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are common uses for tellurium?
Tellurium (Te) is a silvery-white semimetallic element with properties that lie between those of metals and nonmetals. Though adequate supplies of tellurium exist, there is no single major application that creates a large demand for it.
Uses of tellurium:
* Adding small amounts of tellurium increases the ductility of aluminum alloys.
* It hardens tin alloys and increases their tensile strength.
* It improves the machinability of stainless steel and copper.
* It increases the corrosion resistance of lead and manganese-magnesium alloys.
* Bismuth telluride and lead telluride are semiconducting materials used in thermoelectric devices for electricity or cooling.2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How is tellurium important in technology or industry?
Tellurium is a chemical element with properties between those of metals and nonmetals. Though adequate supplies of tellurium exist, there is no single, large application driving demand for it.
Small amounts of tellurium can be added to alloys to improve their properties. For example, it increases the ductility of aluminum alloys, the hardness and tensile strength of tin alloys, and the machinability of stainless steel and copper. It also improves the corrosion resistance of lead and manganese-magnesium alloys. Additionally, bismuth telluride and lead telluride are semiconducting materials used in thermoelectric devices for electricity generation or cooling.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
tellurium (Te), semimetallic chemical element in the oxygen group (Group 16 [VIa] of the periodic table), closely allied with the element selenium in chemical and physical properties. Tellurium is a silvery white element with properties intermediate between those of metals and nonmetals; it makes up approximately one part per billion of Earthâs crust. Like selenium, it is less often found uncombined than as compounds of metals such as copper, lead, silver, or gold and is obtained chiefly as a by-product of the refining of copper or lead. No large use for tellurium has been found.
| atomic number | 52 |
|---|---|
| atomic weight | 127.60 |
| masses of stable isotopes | 120, 122, 123, 124, 125, 126, 128, 130 |
| melting point | 449.8 °C (841.6 °F) |
| boiling point | 989.9 °C (1,813.8 °F) |
| oxidation states | â2, +2, +4, +6 |
| electron configuration | 1s22s22p63s23p63d104s24p64d105s25p4 |
History
The element tellurium was isolated before it was actually known to be an elemental species. About 1782 Franz Joseph MĂŒller von Reichenstein, an Austrian mineralogist, worked with an ore referred to as German gold. From this ore he obtained a material that defied his attempts at analysis and was called by him metallum problematicum. In 1798 Martin Heinrich Klaproth confirmed MĂŒllerâs observations and established the elemental nature of the substance. He named the element after manâs âheavenly bodyâ Tellus, or Earth.
Occurrence and preparation
The demand for tellurium does not match that for selenium. The two elements are found together in many ores; they may be isolated by employing the processes described in connection with selenium, obtaining solutions containing salts of both selenious and tellurous acids, H2SeO3 and H2TeO3. Upon treatment of these solutions with sulfuric acid, tellurium dioxide, TeO2, separates because of its low solubility, while the selenious acid remains dissolved. The tellurium dioxide can be converted into elemental tellurium by treatment with sulfur dioxide; an electrolytic process is used to purify the product.
" height="20" alt="HEW Logo">
Japan, the United States, and Canada are the worldâs largest producers of tellurium.
Physical and chemical properties
In tellurium, the covalent bonding necessary to provide large ring- and chain-molecules by catenation is almost nonexistent. The element crystallizes in the rhombohedral form. It is silvery white and isomorphous with gray seleniumâthat is, the structure and dimensions of the crystals are very similar. It is brittle but not very hard. The tellurium atoms form spiral chains in the crystal with TeâTe distances of 3.74 Ă .
The element is a poor conductor of heat and only a fair conductor of electricity. Tellurium burns in air or in oxygen with a blue-green flame, forming the dioxide (TeO2). It is unaffected by hydrochloric acid, but either nitric acid or aqua regia (a mixture of nitric acid and hydrochloric acid) oxidizes it to tellurous acid (H2TeO3). It reacts with the halogens (fluorine, chlorine, bromine, and iodine) to form halides, and it combines with most metals at elevated temperatures to form tellurides.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
Although there are adequate supplies of the element, no single use has been developed that creates a large demand for it. Small amounts of tellurium increase the ductility of aluminum alloys, the hardness and tensile strength of tin alloys, and the machinability of stainless steel and copper; in lead and in manganese-magnesium alloys, it increases resistance to corrosion. Bismuth telluride and lead telluride are semiconducting materials that have been used in thermoelectric devices either as sources of electricity or for cooling purposes.