The rich chemistry of selenium and tellurium touches various fields in inorganic, (bio)organic, organometallic, and materials chemistry. Since its identification as an essential element, selenium has played a particularly important role in synthetic chemistry and biology. In terms of bonding ...
selenium, 0.64 kg/mt copper for Canada and Chemical uses of selenium, including 0.215 kg/mt copper for the rest of the world. industrial, pharmaceutical, agricultural, and For tellurium, 0.065 kg/mt. World reserves for biological applications, accounted for 10% of selenium are 70,000 tons and resources are domestic usage. Dietary supplements for
Selenium (Se) was identified in 1818 by Berzelius as an elemental residue during the oxidation of sulfur dioxide from copper pyrites in the production of sulfuric acid. It is similar in properties to tellurium (discovered some 35 years earlier) and was named for the moon (selene in Greek) while tellurium had been named for the earth (tellus in Latin).
Selenium is mostly noted for its important chemical properties, especially those dealing with electricity. Unlike sulfur, selenium is a semiconductor, meaning that it conducts some electricity, but not as well as conductors. Selenium is a photoconductor, which means it has the ability to change light energy into electrical energy.
Tellurium; Tennessine ☢ ... Se-74 is used for the production of Se-75 which is used as a source in gamma radiography. Se-76 can be used for the production of the medical isotopes Br-75 and Br-76. Se-82 has been used to study double beta decay. Most of the Selenium isotopes have been used in studies into the role of Selenium as an essential ...
This experiment failed due to substantial loss of tellurium even though the coprecipitation is known 136 Selenium and tellurium content of stony meteorites by neutron activation to be almost complete. The tellurium was probably lost as volatile TeF4 and/or TeFg during the dissolution with HF.
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely occurs in its elemental state or as pure ore ...
Tellurium is present in the Earth's crust only in about 0.001 parts per million. Tellurium minerals include calaverite, sylvanite and tellurite. It is also found uncombined in nature, but only very rarely. It is obtained commercially from the anode muds produced during the electrolytic refining of copper. These contain up to about 8% tellurium.
The Physics of Selenium and Tellurium contains the proceedings of the International Symposium on the Physics of Selenium and Tellurium held in Montreal, Canada, on October 12-13, 1967 and sponsored by the Selenium-Tellurium Development Association, Inc.
An atom of Tellurium in the gas phase, for example, gives off energy when it gains an electron to form an ion of Tellurium. Te + e – → Te – – ∆H = Affinity = 190.2 kJ/mol To use electron affinities properly, it is essential to keep track of sign.
Themed collection Selenium & Tellurium chemistry at the beginning of the 3rd millennium: a celebration of ICCST ... Key developments in the coordination chemistry of the soft, neutral chalcogenoether ligands towards hard s-, f- and early d-block ions, and their prospects for various applications are discussed.
Selenium. Selenium is a non metallic chemical element, member of the group XVI of the periodic table. In chemical activity and physical properties it resembles sulfur and tellurium.Selenium appearsin a number of allotropic forms: the most popular are a red amorphous powder, a red crystalline material, and a gray crystalline metallike form called metallic selenium.
Neutron scattering experiments for liquid tellurium-selenium mixtures have been carried out in the semiconductor-to-metal transition range. The dynamic structure of liquid Te 50 Se 50 at three temperatures (semiconducting, transition and metallic regime) was measured. We also measured the dynamic structure factor of liquid Te (metallic regime) and liquid Te 40 Se 60 (semiconducting regime) …
He also noted that it was like sulfur and indeed had properties intermediate between sulfur and tellurium. Berzelius found that selenium was present in samples of tellurium and gave that element its characteristic smell. ... The energy released when an electron is added to the neutral atom and a negative ion is formed. Electronegativity ...
The Phonon Spectra of Trigonal Selenium and Tellurium Photoluminescence of Selenium and Selenium-Tellurium Mixed Crystals Light Beam Modulation in Trigonal Selenium Investigations on Crystalline Tellurium and Solid Amorphous and Liquid Selenium with Inelastic Neutron Scattering
Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid.Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens.It is occasionally found in native form as elemental crystals.
selenium and tellurium content of stony meteorites by neutron activation to be almost complete. The tellurium was probably lost as volatile TeF, and/or TeF, during the dissolution with HF. RESULTS AND DISCUSSION The results of the Se and Te activation analysis for several of the stony meteor-
Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared range and their stability against crystallization.
Tellurium. Tellurium is the metalloid of the oxygen family, with a silvery white color and a metallic luster similar to that of tin at room temperature. Like selenium, it is also displays photoconductivity. Tellurium is an extremely rare element, and is most commonly found as a telluride of gold.
Selenium's legal airborne permissible exposure limit (PEL) is 0.2 mg m-3 averaged over an 8-hour shift. The EPA describes selenium as not classifiable for human carcinogenicity. Selenium sulfide is a probable carcinogen. Many of selenium's compounds, such as selenates and selenites, are highly toxic.
Number of Neutrons Melting Point Boiling Point Date of Discovery Crystal Structure. Element Groups: Alkali Metals Alkaline Earth Metals Transition Metals Other Metals ... I currently do not know of any links for Selenium. If you do, please let me know MLA Format for Citing This Page Bentor, Yinon. Chemical Element.com - Selenium.
Hydrogen selenide (H 2 Se) Sodium selenite (Na 2 SeO 3) Selenious acid (H 2 SeO 3) Selenium trioxide (SeO 3) Interesting facts: It is similar to sulfur in its form and compounds. It converts light into electricity. It decreases electrical resistance with increased illumination. It can convert AC electricity to DC electricity.
high purity radioactive iodine-131 is obtained in a stable chemical form by the dry distillation of a neutronirradiated tellurium containing meterial, such as tellurium dioxide, onto alumina followed by elution with a base such as dilute alkaline solution. radioactive iodine-131 can be prepared by this process with a minimum of radioactive contamination to the immediate environment.
He decided that tellurium was a metal, but belonged in the same group as the nonmetals sulfur and selenium due to the similarities of their compounds. (5) We now class tellurium as a metalloid because, as the confused scientists of the 1700s first noticed, it has properties that sit …