1 decade ago. Small amounts of organoselenium compounds have been used to modify the catalysts used for the vulcanization for the production of rubber.. Answer Save. This was followed by the discovery of selenocysteine in proteins.  The LiâSe battery is an alternative to the lithiumâsulfur battery, with an advantage of high electrical conductivity. Metal. ), Selenium may inhibit Hashimoto's disease, in which the body's own thyroid cells are attacked as foreign. In fact, 16.7% of the worlds animal protein intake came from fish in 2010. , Certain species of plants are considered indicators of high selenium content of the soil because they require high levels of selenium to thrive. CONTENTS. The selenium cell was used in the photophone developed by Alexander Graham Bell in 1879.  Ruminants are particularly susceptible. In 1873, Willoughby Smith found that the electrical resistance of grey selenium was dependent on the ambient light. 31 During this period (1930s) the toxicity of metals and metalloids was being evaluated for animal disease and nutrition. â¦ What channel number is One America News on Dish Network? Are gases metal or metalloid? The Se concentration in soil varies with type, texture and organic matter content of the soil and with rainfall. Selenium shows borderline metalloid or nonmetal behaviour. Join â¦ 4. It's a gas, honey. Like sulfur and phosphorus it is solid but nonetheless a non metal. Is Selenium A Metal. Another source was the mud from the lead chambers of sulfuric acid plants, a process that is no longer used.  The resultant high selenium levels in waterways were found to cause congenital disorders in oviparous species, including wetland birds and fish. These findings suggest that, with the exception of vertebrates, aquatic life supports selenium use, whereas terrestrial habitats lead to reduced use of this trace element. ), and false goldenweed (Oonopsis sp.  Since its invention, solvent extraction and electrowinning (SX/EW) production of copper produces an increasing share of the worldwide copper supply. The National Institute for Occupational Safety and Health (NIOSH) has set a Recommended exposure limit (REL) of 0.2 mg/m3 over an 8-hour workday. A previous sharp increase was observed in 2004 from $4â$5 to $27/lb. Asked By adminstaff @ 01/01/2020 02:35 AM. Nonmetal. , 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. Selenium (Se³â´ââ) is a metalloid which is close to sulfur (S) in terms of properties. These data exclude two major producers: the United States and China. Ask Question + 100. Analysis of blood levels of inorganic compounds in the supplement indicated the selenium concentrations were 10 to 15 times higher than normal in the blood samples, and 15 to 20 times higher than normal in the liver samples. The US Recommended Dietary Allowance (RDA) of selenium for teenagers and adults is 55 Âµg/day. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids. Selenium is a chemical element with the symbol Se and atomic number 34. Tags: Question 8 . 30 seconds . , Researchers found that application of selenium fertilizer to lettuce crops decreased the accumulation of lead and cadmium. Sheets of amorphous selenium convert X-ray images to patterns of charge in xeroradiography and in solid-state, flat-panel X-ray cameras. 0 0. Selenium is a metalloid element with the atomic number 34. Selenium enzymes are involved in the small reducing molecules glutathione and thioredoxin.  It has also been suggested that season could have an impact on the harmful effects of selenium on fish. Their use continued into the 1990s. The common mineral selenite is not a selenium mineral, and contains no selenite ion, but is rather a type of gypsum (calcium sulfate hydrate) named like selenium for the moon well before the discovery of selenium. Substantial physiological changes may occur in fish with high tissue concentrations of selenium. It moves through the aquatic environment similarly to arsenic and antimony; its water-soluble salts, in higher concentrations, have a similar toxicological profile to that of arsenic. Reproduction of mallard ducks is impaired at dietary concentrations of 7 ug Se/L. Arsenic is a metalloid element. Selenium was also recognized as an important veterinary toxin, which is seen in animals that have eaten high-selenium plants. Ca.  Ocean water contains significant amounts of selenium. It is in the p block. Selenium is most commonly found as an impurity, replacing a small part of the sulfur in sulfide ores of many metals. ), woody asters (Xylorhiza sp. , In the regions (e.g. [clarification needed]. selene meaning "Moon") was discovered in 1817 by JÃ¶ns Jacob Berzelius and Johan Gottlieb Gahn. For this purpose, various selenite and selenate salts are added. Se, C and P have very similar metallic properties. selenium (such as carbon, phosphorus and iodine) is considered 0 0. China is the largest consumer of selenium dioxide for this purpose. Sedimentary. 3. , Increased dietary selenium reduces the effects of mercury toxicity, although it is effective only at low to modest doses of mercury. However, it can damage plants at higher doses. The first commercial products using selenium were developed by Werner Siemens in the mid-1870s. , 75Se is used with bismuth in brasses to replace more toxic lead longer when in storage significant of! 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