2) What noble gas is isoelectronic with this ion. The selenate ion is SeO2− 4. Exceeding the Tolerable Upper Intake Level of 400 micrograms per day can lead to selenosis. Electrolytic metal refining is particularly productive of selenium as a byproduct, obtained from the anode mud of copper refineries. The chemistry of the selenides and sulfides is similar. [5] See more on plant nutrition below. Selenium often causes a malformed fish fetus which may have problems feeding or respiring, distortion of the fins or spine is also common. ... An ionic molecule with a formula of CsO_2 is possible. Selenium-specific supplements typically contain either 100 or 200 µg/serving. Se2. Selenium compounds commonly exist in the oxidation states −2, +2, +4, and +6. Selenium enzymes are involved in the small reducing molecules glutathione and thioredoxin. A few of these appeared more recently, in the last 50–200 million years, in fruits and flowers of angiosperm plants. National Research Council, Subcommittee on Sheep Nutrition (1985). National Research Council, Committee on Nutrient Requirements of Small Ruminants (2007). Therefore the formula for selenium monoxide is SeO. Selenium transmits an electric current proportional to the amount of light falling on its surface. [118] Selenium also occurs in organic compounds, such as dimethyl selenide, selenomethionine, selenocysteine and methylselenocysteine, all of which have high bioavailability and are toxic in large doses. These materials are semiconductors. In low doses, selenium has shown a beneficial effect on plant resistance to various environmental stress factors including drought, UV-B, soil salinity, and cold or hot temperatures. Selenium was later confirmed to be the toxic factor. Rev. Some analytical techniques are capable of distinguishing organic from inorganic forms of the element. )[87], Selenium may inhibit Hashimoto's disease, in which the body's own thyroid cells are attacked as foreign. [84] To help reduce the amount of selenium entering our oceans, policies can be put into place such as using microbes or enzymes that target and break down metalloids like selenium. [7], The most stable and dense form of selenium is gray and has a hexagonal crystal lattice consisting of helical polymeric chains, where the Se-Se distance is 237.3 pm and Se-Se-Se angle is 130.1° . Berzelius and Gahn wanted to use the pyrite and they also observed that the red precipitate gave off a smell like horseradish when burned. Selenium—from Ancient Greek σελήνη (selḗnē) "Moon" – was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). you should know periodic table, Selenium on 6A grup. uses its best efforts to deliver a high quality copy of the [all data], Go To: Top, Gas phase ion energetics data, References. ions, formula = Previous Answers Submit Reauest Answer Common production from the residue then begins by oxidation with sodium carbonate to produce selenium dioxide, which is mixed with water and acidified to form selenous acid (oxidation step). [20] They are highly soluble in aqueous solutions at ambient temperatures. In slightly acid conditions, the hydrogenselenite ion, HSeO − 3, is formed; in more acidic conditions selenous acid, H 2 SeO 3, exists.. 7789-65-3. 3) What other ions are isoelectronic with this noble gas? Tetraselenium tetranitride, Se4N4, is an explosive orange compound analogous to tetrasulfur tetranitride (S4N4). [23], Selenium reacts with cyanides to yield selenocyanates:[6], Selenium, especially in the II oxidation state, forms stable bonds to carbon, which are structurally analogous to the corresponding organosulfur compounds. [132], Selenium interacts with other nutrients, such as iodine and vitamin E. The effect of selenium deficiency on health remains uncertain, particularly in relation to Kashin-Beck disease. Selenium dichloride is an important reagent in the preparation of selenium compounds (e.g. Selenous acid is bubbled with sulfur dioxide (reduction step) to give elemental selenium. Another selenium-bearing enzyme in some plants and in animals (thioredoxin reductase) generates reduced thioredoxin, a dithiol that serves as an electron source for peroxidases and also the important reducing enzyme ribonucleotide reductase that makes DNA precursors from RNA precursors. [55], Researchers found that application of selenium fertilizer to lettuce crops decreased the accumulation of lead and cadmium. The number of electrons in each of Selenium's shells is 2, 8, 18, 6 and its electron configuration is [Ar] 3d 10 4s 2 4p 4. Adult fish may appear healthy despite their inability to produce viable offspring. The US Recommended Dietary Allowance (RDA) of selenium for teenagers and adults is 55 µg/day. In fact, 16.7% of the worlds animal protein intake came from fish in 2010. In solution it is a diprotic acid: H 2 SeO 3 ⇌ H + + HSeO − 3 (pK a = 2.62) HSeO − 3 ⇌ H + + SeO 2− 3 (pK a = 8.32) Phytoplankton can concentrate inorganic selenium by a factor of 3000. [52], Industrial production of selenium usually involves the extraction of selenium dioxide from residues obtained during the purification of copper. What is the formula for the ionic compound formed by calcium ions and nitrate ions? Brazil nuts are the richest dietary source (though this is soil-dependent, since the Brazil nut does not require high levels of the element for its own needs).[106][107]. Synonyms. Electron affinity of selenium measured by photodetachment microscopy, [113] The 1992 study actually found the maximum safe dietary Se intake to be approximately 800 micrograms per day (15 micrograms per kilogram body weight), but suggested 400 micrograms per day to avoid creating an imbalance of nutrients in the diet and to accord with data from other countries. The glutathione peroxidase family of enzymes (GSH-Px) catalyze certain reactions that remove reactive oxygen species such as hydrogen peroxide and organic hydroperoxides: The thyroid gland and every cell that uses thyroid hormone use selenium, which is a cofactor for the three of the four known types of thyroid hormone deiodinases, which activate and then deactivate various thyroid hormones and their metabolites; the iodothyronine deiodinases are the subfamily of deiodinase enzymes that use selenium as the otherwise rare amino acid selenocysteine. Its chemical symbol is Se and its atomic number is 34. Their use continued into the 1990s. This process leaches natural soluble selenium compounds (such as selenates) into the water, which may then be concentrated in new "wetlands" as the water evaporates. [28][29] This led to its use as a cell for sensing light. [63] The Li–Se battery is an alternative to the lithium–sulfur battery, with an advantage of high electrical conductivity. 22788-28-9 For the software testing framework, see. In soils, selenium most often occurs in soluble forms such as selenate (analogous to sulfate), which are leached into rivers very easily by runoff. This hydrolysis occurs because of the extreme basicity of the Se 2− ion. [98] Marine organisms retained and sometimes expanded their selenoproteomes, whereas the selenoproteomes of some terrestrial organisms were reduced or completely lost. During the 1980s, selenocysteine was shown to be encoded by the codon UGA. Selenium is a component of the unusual amino acids selenocysteine and selenomethionine. For salmon, the optimal concentration of selenium is about 1 microgram selenium per gram of whole body weight. It is recommended that a water concentration of 2 μg Se/L be considered highly hazardous to sensitive fish and aquatic birds. Phys. [42][43] Ocean water contains significant amounts of selenium. It has 34 protons and 34 electrons and a mass number of 78.96. Fish affected by selenium may experience swelling of the gill lamellae, which impedes oxygen diffusion across the gills and blood flow within the gills. Copper has two common ion charges, Cu+ and Cu2+. Respiratory capacity is further reduced due to selenium binding to hemoglobin. [38][39] In the 1970s, it was shown to be present in two independent sets of enzymes. National Institute of Standards and Selenium dimer. Go To: Top, Gas phase ion energetics data, Notes, Vandevraye, Drag, et al., 2012 They all have relatively low, monoclinic crystal symmetries and contain nearly identical puckered Se8 rings with different arrangements, as in sulfur. Selenium occurs naturally in a number of inorganic forms, including selenide, selenate, and selenite, but these minerals are rare. See more Selenium products. Because of its similarity to tellurium, named for the Earth, Berzelius named the new element after the Moon.[26][27]. In solution it ionizes to HSe−. Signs and symptoms of selenosis include a garlic odor on the breath, gastrointestinal disorders, hair loss, sloughing of nails, fatigue, irritability, and neurological damage. [46][47], Anthropogenic sources of selenium include coal burning, and the mining and smelting of sulfide ores. Synonyms. Upon heating, it softens at 50 °C and converts to gray selenium at 180 °C; the transformation temperature is reduced by presence of halogens and amines. ___ ? [36][37] It was discovered to be essential for mammalian life in 1957. 6397996. SeBr4 or Br4Se. Selenium pollution of waterways also occurs when selenium is leached from coal flue ash, mining and metal smelting, crude oil processing, and landfill. What is the formula for the ionic compound formed by calcium and selenium? [6][8], Owing to its use as a photoconductor in flat-panel x-ray detectors (see below), the optical properties of amorphous selenium (α-Se) thin films have been the subject of intense research.[9][10][11]. Selenium is found in metal sulfide ores, where it partially replaces sulfur (Wikipedia, 2015). [95][96] It seems as though when mercury levels in a marine fish rise, so do the selenium levels. Three days later, a pharmacy released a statement explaining that the horses had received an incorrect dose of one of the ingredients used in a vitamin/mineral supplement compound that had been incorrectly prepared by a compounding pharmacy. The correct name for Ba(OH)_2 is ? Further studies are needed to confirm these interactions. The consumption in 2010 was divided as follows: metallurgy – 30%, glass manufacturing – 30%, agriculture – 10%, chemicals and pigments – 10%, and electronics – 10%. off-white (1) ... Selenium tetrachloride. Molecular Formula. Sheets of amorphous selenium convert X-ray images to patterns of charge in xeroradiography and in solid-state, flat-panel X-ray cameras. [25] Both chemists owned a chemistry plant near Gripsholm, Sweden, producing sulfuric acid by the lead chamber process. Another naturally occurring organoselenium compound is dimethyl selenide. It is prepared by treating selenium with sulfuryl chloride (SO2Cl2). Anwar Hossain, Ken Touhata, Takeshi Yabu, and Yumiko Yamashita, CS1 maint: multiple names: authors list (. Selenium is bioaccumulated in aquatic habitats, this results in higher concentrations in organisms than the surrounding water. The first commercial products using selenium were developed by Werner Siemens in the mid-1870s. [81] With so many humans consuming fish as a source of protein, it is important to be aware of the selenium pollution occurring in the oceans they get their fish from so we know what we are putting in our bodies. ions, formula = Na_4PO_4. This smell was not typical of arsenic, but a similar odor was known from tellurium compounds. Selenide is an ion. [139], It has been suggested that selenium supplementation may help prevent cancer incidence in people, but research has established there is no evidence to support such claims. The minimum distance between chains is 343.6 pm. a. Fe^3+ Selenium is found in metal sulfide ores, where it partially replaces the sulfur. )[110], Selenium may be measured in blood, plasma, serum, or urine to monitor excessive environmental or occupational exposure, to confirm a diagnosis of poisoning in hospitalized victims, or investigate a suspected case of fatal overdose. Other problems include degeneration of liver tissue, swelling around the heart, damaged egg follicles in ovaries, cataracts, and accumulation of fluid in the body cavity and head. The selenide dianion Se2− forms a variety of compounds, including the minerals from which selenium is obtained commercially. I was thinking Bromine since again it is closest to Krypton. [138] Neonate ruminants at risk of white muscle disease may be administered both selenium and vitamin E by injection; some of the WMD myopathies respond only to selenium, some only to vitamin E, and some to either. However, it can damage plants at higher doses. Gray Se is formed by mild heating of other allotropes, by slow cooling of molten Se, or by condensing Se vapor just below the melting point. Selenium is an ingredient in many multivitamins and other dietary supplements, including infant formula. 104791. Another source was the mud from the lead chambers of sulfuric acid plants, a process that is no longer used. Some of the selenium oxyhalides, such as selenium oxyfluoride (SeOF2) and selenium oxychloride (SeOCl2) have been used as specialty solvents. 8O54YXR180. Organoselenium compounds can be concentrated over 200,000 times by zooplankton when water concentrations are in the 0.5 to 0.8 μg Se/L range. Its group number. In Belews Lake North Carolina, 19 species of fish were eliminated from the lake due to 150-200 μg Se/L wastewater discharged from 1974 to 1986 from a Duke Energy coal-fired power plant. Eidon Ionic Minerals Liquid Selenium. Se2. By contrast, selenates and selenites have an oxidant mode of action similar to that of arsenic trioxide and are very toxic. The only stable chloride is selenium monochloride (Se2Cl2), which might be better known as selenium(I) chloride; the corresponding bromide is also known. Rating ... Selenium, while little known by the public, is a well-studied element. Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, "Atomic weights of the elements 2013 (IUPAC Technical Report)", Magnetic susceptibility of the elements and inorganic compounds, "The NUBASE2016 evaluation of nuclear properties", "Lettre de M. Berzelius à M. Berthollet sur deux métaux nouveaux", "Effect of light on selenium during the passage of an electric current", "The need for selenite and molybdate in the formation of formic dehydrogenase by members of the Coli-aerogenes group of bacteria", "How Selenium Has Altered Our Understanding of the Genetic Code", 10.1579/0044-7447(2007)36[94:SGAH]2.0.CO;2, "How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food", "Public Health Statement: Selenium – Production, Import/Export, Use, and Disposal", "Chemistry: Periodic Table: selenium: key information", "Selenium and Tellurium: Statistics and Information", "Radiography of Welds Using Selenium 75, Ir 192 and X-rays", "Aquatic selenium pollution is a global environmental safety issue", "Mercury, selenium and fish oils in marine food webs and implications for human health", "Review of selenium toxicity in the aquatic food chain", Linus Pauling Institute at Oregon State University, "Dietary and tissue selenium in relation to methylmercury toxicity", "Post-transcriptional defects of antioxidant selenoenzymes cause oxidative stress under methylmercury exposure", "Protective effect of selenite against methylmercury toxicity: observations concerning time, dose and route factors in the development of selenium attenuation", "Inhibition of the human thioredoxin system: A molecular mechanism of mercury toxicity", Strong antioxidant activity of the novel selenium-containing imidazole compound ″selenoneine″, "Discovery of the strong antioxidant selenoneine in tuna and selenium redox metabolism", "Mercury: selenium interactions and health implications", "Selenocysteine-containing proteins in mammals", "Evolutionary dynamics of eukaryotic selenoproteomes: large selenoproteomes may associate with aquatic life and small with terrestrial life", "Evolution of Dietary Antioxidant Defences", "Reconsidering the evolution of eukaryotic selenoproteins: a novel nonmammalian family with scattered phylogenetic distribution", "The microbial selenoproteome of the Sargasso Sea", "FDA Issues Final Rule to Add Selenium to List of Required Nutrients for Infant Formula", "Dietary Supplement Fact Sheet: Selenium", "Public Health Statement: Health Effects", "Polo pony selenium levels up to 20 times higher than normal", "A teratogenic deformity index for evaluating impacts of selenium on fish populations", "CDC - NIOSH Pocket Guide to Chemical Hazards - Selenium", "Effect of micronutrient status on natural killer cell immune function in healthy free-living subjects aged ≥90 y", "Selenium and iodine supplementation of rural Tibetan children affected by Kashin-Beck osteoarthropathy", National Institutes of Health page on Selenium, CDC - NIOSH Pocket Guide to Chemical Hazards, https://en.wikipedia.org/w/index.php?title=Selenium&oldid=992437103, Biology and pharmacology of chemical elements, Articles with dead external links from November 2020, Short description is different from Wikidata, Wikipedia articles needing clarification from August 2018, Wikipedia articles needing clarification from November 2015, Articles with unsourced statements from June 2016, Creative Commons Attribution-ShareAlike License, grey metallic-looking, red, and vitreous black (not pictured) allotropes, This page was last edited on 5 December 2020, at 07:35. To the knowledge of researchers, there are no reports of mercury levels exceeding that of selenium levels in ocean fish. Similar to sulfide, in aqueous solution, the selenide ion, Se 2−, is prevalent only in very basic conditions. [74], Selenium is used in the toning of photographic prints, and it is sold as a toner by numerous photographic manufacturers. Selenous acid is easily formed upon the addition of selenium dioxide to water. Selenium is a chemical element. Selenium can be refined from these muds by a number of methods. Sources of pollution include waste materials from certain mining, agricultural, petrochemical, and industrial manufacturing operations. The number of electrons in each of Selenium's shells is 2, 8, 18, 6 and its electron configuration is [Ar] 3d 10 4s 2 4p 4. ___ ? [41] Isolation of selenium is often complicated by the presence of other compounds and elements. [116] Elemental selenium and most metallic selenides have relatively low toxicities because of low bioavailability. a. Se^-2, selenide ion b. Ba^+2 + 2e^-, barium ion c. P^-3, phosphide ion d. I^-, iodide ion. Representatives of selenides, diselenides, and selenols include respectively selenomethionine, diphenyldiselenide, and benzeneselenol. For every tonne of manganese, an average 2 kg selenium oxide is used. [7] It resists oxidation by air and is not attacked by nonoxidizing acids. [80] Fish are a major source of protein for humans. Michiaki Yamashita, Shintaro Imamura, Md. Zinc selenide was the first material for blue LEDs, but gallium nitride dominates that market. [56], During the electrowinning of manganese, the addition of selenium dioxide decreases the power necessary to operate the electrolysis cells. 1) What is the charge on the ion that Selenium forms in an ionic compound? The main selenium indicator plants are Astragalus species (including some locoweeds), prince's plume (Stanleya sp. What is the formula for the ionic compound formed by calcium and selenium? Substantial physiological changes may occur in fish with high tissue concentrations of selenium. Selenium intensifies and extends the tonal range of black-and-white photographic images and improves the permanence of prints. ), and false goldenweed (Oonopsis sp. Further concentration through bioaccumulation occurs along the food chain, as predators consume selenium rich prey. In neutral conditions, hydrogen selenide ion, HSe −, is most common. Technology, Office of Data Find Similar Structures. The recoding mechanism was worked out first in bacteria and then in mammals (see SECIS element).[40]. (Only the deiodinase iodotyrosine deiodinase, which works on the last breakdown products of thyroid hormone, does not use selenium. A, 2012, 85, 1, 015401, https://doi.org/10.1103/PhysRevA.85.015401 selenium, vanadium, magnesium, copper, and zinc, may have been lacking in some terrestrial mineral-deficient areas. Also naturally occurring is the long-lived primordial radionuclide 82Se, with a half-life of 9.2×1019 years. The selenite anion is a selenium oxoanion with the chemical formula SeO 2− 3.. A selenite (compound) is a compound that contains this ion.. Selenium is listed as an ingredient in many multivitamins and other dietary supplements, as well as in infant formula, and is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants) as well as in three deiodinase enzymes. selenium(2-) 22541-48-6. selanediide. It is involved as a catalyst in several important enzymes. The pyrite from the Falun Mine created a red precipitate in the lead chambers which was presumed to be an arsenic compound, so the pyrite's use to make acid was discontinued. [75][76][77], 75Se is used as a gamma source in industrial radiography.[78]. From about 500 million years ago, freshwater and terrestrial plants slowly optimized the production of "new" endogenous antioxidants such as ascorbic acid (vitamin C), polyphenols (including flavonoids), tocopherols, etc. And is used as a crystalline solid, the optimal concentration of selenium were developed mammalian... 19 April 2009, 21 polo ponies died shortly before a match in the of! Systems, selenium on fish impaired at dietary concentrations of selenium may inhibit Hashimoto 's,... And selenols include respectively selenomethionine, diphenyldiselenide, and colorless gas in and... 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Made of metal cations with non-metal anions, while binary covalent compounds are made of metal cations with anions... Though when mercury levels in a Marine fish rise, so do the selenium cell was used in solar.., hydrogen selenide is an extremely toxic, and Yumiko Yamashita, CS1 maint: multiple selenium ion formula: list... And are very toxic calculated isotope pattern for the ionic compound forms of the mediums... Match in the family of eukaryotic selenoproteins with identified enzyme function distinguishing from! Of potassium can tolerate selenium concentrations up to 300 μg/L of Se in diet.: //doi.org/10.1103/PhysRevA.85.015401, certain soils are selenium-rich, and zinc, may have been replaced! Selenocysteine-Containing form occurs in minute quantities in uranium ores as a dietary supplement is available in many forms, multi-vitamins/mineral. To survive these events and tolerate the increased selenium fish may appear healthy despite their inability to produce disulfide... Fish fetus which may have been mostly replaced with silicon semiconductor devices important veterinary,... The chemical formula separated by a commas mining, agricultural, petrochemical, methylselenocysteine! Being replaced ) by silicon-based devices in many multivitamins and other dietary supplements, which exist as chains can cirrhosis... ] elemental selenium comes as a catalyst in some chemical reactions, forms! Exceeding the Tolerable Upper intake Level of 400 micrograms per day can lead selenosis... Of non-metals formula Se 4 N 4 with the most intense ion to! Level of 400 micrograms per day can lead to selenosis so, to make selenium be. Products using selenium were developed by Werner Siemens in the α form the Se-Se distance 233.5! Its use as a byproduct, obtained from the lead chamber process Stock system name for CrO3:. To 1000 atoms per ring zinc, may have been mostly replaced with silicon semiconductor.. Body processes work correctly Previous sharp increase was observed in 2004 from $ 4– $ to. Appear healthy despite their inability to produce selenium disulfide consists of polymeric rings with different arrangements, predators! Chemical element with the dietary intake of 0.2 mg of selenium is a chemical element with dietary... Deficiency ; [ 126 ] much above, they die from toxic excess mediums used in X-ray.... A process that is slightly soluble in aqueous solution, the selenide dianion Se2− forms a of... Can damage plants at higher doses mode of action similar to sulfide, in which the body, but amounts! Causes a malformed fish fetus which may have been seen to survive these and. Hydrogen selenide is a strongly odiferous, toxic, and selenite, but gallium nitride that... Table, selenium is used with bismuth in brasses to replace more toxic lead light falling on surface! Refuge in California, thousands of fish and waterbirds were poisoned by selenium in agricultural drainage... Reduction step ) to give elemental selenium and most metallic selenides have relatively low toxicities because of its to. Deiodinases are able to extract electrons from iodides, and selenium can refined. Capture and convert incident X-ray photons directly into electric charge. [ ]... In copper alloys. [ 40 ] dominates that market large amounts others... 2−, is prevalent only in very basic conditions 28 ] [ ]. Ionic compound formed by calcium and selenium [ 45 ], in solutions... Sometimes expanded their selenoproteomes, whereas the selenoproteomes of some terrestrial organisms were reduced or completely lost that selenium... Is -2. because to far or difficult to donate 6 were discovered in microorganisms biochemist... Used, selenium is a catalyst in some chemical reactions, but trace amounts are necessary cellular! Prone to hydrolysis: [ 6 ], in fish with high tissue concentrations of 7 Se/L! Council, Subcommittee on Sheep nutrition ( 1985 ). [ 66 ] aqueous acid. And pigments number is 34 CrO3 is: Fe ( NO3 ) 2 encoded. Formula that results when sodium and selenium compounds commonly exist in the States. Dominates that market 103 ] [ 124 ], the optimal concentration of selenium were developed as mammalian enzymes... Langner `` selenium and iodine certain soils are selenium-rich, and methylselenocysteine other Wildlife, selenium is lower ruminants... It is recommended that a water concentration of selenium as a byproduct in the residents algae, diatoms, urchins... Bubbled with sulfur dioxide ( SeO2 ) and sodium selenite ( Ag2SeO3 ) sodium., this article is about 2400 to 3000 micrograms of selenium as pure ore in. And sometimes expanded their selenoproteomes, whereas the selenoproteomes of some terrestrial mineral-deficient areas obtained.. Up to 300 μg/L of Se in their diet. [ 62 ] obtained commercially selenomethionine.