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Its properties are thus intermediate between those of chlorine and iodine. Arsenic is a metalloid. Nobelium is the tenth transuranic element and is the penultimate member of the actinide series. 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. www.nuclear-power.net. It occurs on Earth as the decay product of various heavier elements. Respiratory capacity is further reduced due to selenium binding to hemoglobin. [93][94] An antioxidant, selenoneine, which is derived from selenium and has been found to be present in the blood of bluefin tuna, is the subject of scientific research regarding its possible roles in inflammatory and chronic diseases, methylmercury detoxification, and oxidative damages. Very soft and malleable, indium has a melting point higher than sodium and gallium, but lower than lithium and tin. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Name: Selenium. Gold is a chemical element with atomic number 79 which means there are 79 protons and 79 electrons in the atomic structure. The atomic mass is the mass of an atom. Atomic Properties; Electronegativity (Pauling scale): 2.55: Atomic Radius: 103 pm: Ionic Radius: 198 pm (-2) Van der Waals Radius: 190 pm: 1st Ionization energy: 941 kJ/mol: 1st Electron affinity:-195 kJ/mol: Oxidation States:-2,2,4,6: Physical Properties; Standard State: solid: Bonding Type: metallic: Melting Point: 494 K: Boiling Point: 958 K: Density: 4.82 g/cm 3: Metal/Non-Metal: nonmetal: Osmium is a chemical element with atomic number 76 which means there are 76 protons and 76 electrons in the atomic structure. To the knowledge of researchers, there are no reports of mercury levels exceeding that of selenium levels in ocean fish. Carbon is a chemical element with atomic number 6 which means there are 6 protons and 6 electrons in the atomic structure. The chemical symbol for Radon is Rn. This equilibrium also known as “samarium 149 reservoir”, since all of this promethium must undergo a decay to samarium. Anwar Hossain, Ken Touhata, Takeshi Yabu, and Yumiko Yamashita, CS1 maint: multiple names: authors list (. The chemical symbol for Iodine is I. Iodine is the heaviest of the stable halogens, it exists as a lustrous, purple-black metallic solid at standard conditions that sublimes readily to form a violet gas. The selenide dianion Se2− forms a variety of compounds, including the minerals from which selenium is obtained commercially. Whereas other Se forms are insulators, gray Se is a semiconductor showing appreciable photoconductivity. The chemical symbol for Promethium is Pm. One atomic mass unit is equal to 1.66 x 10-24 grams. High doses of Se supplements in pregnant animals might disturb the Zn:Cu ratio and lead to Zn reduction; in such treatment cases, Zn levels should be monitored. [117] Hydrogen selenide is an extremely toxic, corrosive gas. It is a soft metalloid similar to sulfur, unaffected by water and soluble in alkalis and nitric acid. Argon is the third-most abundant gas in the Earth’s atmosphere, at 0.934% (9340 ppmv). China is the dominant consumer of selenium at 1,500–2,000 tonnes/year. The chemical symbol for Cobalt is Co. Cobalt is found in the Earth’s crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. Holmium is a chemical element with atomic number 67 which means there are 67 protons and 67 electrons in the atomic structure. For this purpose, various selenite and selenate salts are added. Mercury is a chemical element with atomic number 80 which means there are 80 protons and 80 electrons in the atomic structure. Selenium's semiconductor properties found numerous other applications in electronics. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226. Natural boron consists primarily of two stable isotopes, 11B (80.1%) and 10B (19.9%). We assume no responsibility for consequences which may arise from the use of information from this website. The metal is found in the Earth’s crust in the pure, free elemental form (“native silver”), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Selenium is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. For example, the neutron number of uranium-238 is 238-92=146. The most commonly used spontaneous fission neutron source is the radioactive isotope californium-252. Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. The only stable chloride is selenium monochloride (Se2Cl2), which might be better known as selenium(I) chloride; the corresponding bromide is also known. However, the lack of tellurium compounds in the Falun Mine minerals eventually led Berzelius to reanalyze the red precipitate, and in 1818 he wrote a second letter to Marcet describing a newly found element similar to sulfur and tellurium. [102][103][104][105], Dietary selenium comes from meat, nuts, cereals and mushrooms. Titanium condenser tubes are usually the best technical choice, however titanium is very expensive material. [116] Elemental selenium and most metallic selenides have relatively low toxicities because of low bioavailability. Calcium is a chemical element with atomic number 20 which means there are 20 protons and 20 electrons in the atomic structure. The standard SI unit is kilograms per cubic meter (kg/m3). Magnesium is a chemical element with atomic number 12 which means there are 12 protons and 12 electrons in the atomic structure. Thorium metal is silvery and tarnishes black when exposed to air, forming the dioxide. The chemical symbol for Palladium is Pd. Their use continued into the 1990s. Zirconium is a chemical element with atomic number 40 which means there are 40 protons and 40 electrons in the atomic structure. The chemical symbol for Cadmium is Cd. 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. Iodine is the least abundant of the stable halogens, being the sixty-first most abundant element. Gold is a transition metal and a group 11 element. [112] This 400 µg Tolerable Upper Intake Level is based primarily on a 1986 study of five Chinese patients who exhibited overt signs of selenosis and a follow up study on the same five people in 1992. Number of Neutrons: 45. the preparation of Se7). Holmium is a part of the lanthanide series, holmium is a rare-earth element. Because of its similarity to tellurium, named for the Earth, Berzelius named the new element after the Moon.[26][27]. (1969), Discoverer: Scientists at Dubna, Russia (1967)/Lawrence Berkeley Laboratory (1970), Discoverer: Armbruster, Paula and Muenzenberg, Dr. Gottfried, Element Category: unknown, probably a transition metal, Discoverer: David Anderson, Ruhani Rabin, Team Updraft, Element Category: unknown, probably a post-transition metal, Discoverer: Hisinger, Wilhelm and Berzelius, Jöns Jacob/Klaproth, Martin Heinrich. It explains how we use cookies (and other locally stored data technologies), how third-party cookies are used on our Website, and how you can manage your cookie options. The difference is a measure of the nuclear binding energy which holds the nucleus together. Selenium is not an abundant element. Fermium is a chemical element with atomic number 100 which means there are 100 protons and 100 electrons in the atomic structure. [24], Selenium (Greek σελήνη selene meaning "Moon") was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn. Know what is Selenium, Chemical Properties of Selenium, Atomic Mass, and more at BYJU'S The chemical symbol for Terbium is Tb. A reduction of 21% on TPO antibodies is reported with the dietary intake of 0.2 mg of selenium. Selenium is in period 4 on the periodic table. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. The sulfoxide in sulfur chemistry is represented in selenium chemistry by the selenoxides (formula RSe(O)R), which are intermediates in organic synthesis, as illustrated by the selenoxide elimination reaction. Atomic Number of Selenium is 34. Nitrogen is a chemical element with atomic number 7 which means there are 7 protons and 7 electrons in the atomic structure. They all have relatively low, monoclinic crystal symmetries and contain nearly identical puckered Se8 rings with different arrangements, as in sulfur. [100] Marine fishes and vertebrate thyroid glands have the highest concentration of selenium and iodine. Niobium is a soft, grey, ductile transition metal, often found in the minerals pyrochlore (the main commercial source for niobium) and columbite. The colour ranges from grey metallic to red glassy. Thallium is a soft gray post-transition metal is not found free in nature. Selenium occurs naturally in a number of inorganic forms, including selenide, selenate, and selenite, but these minerals are rare. Zirconium is widely used as a cladding for nuclear reactor fuels. 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. [55][57], The largest commercial use of Se, accounting for about 50% of consumption, is for the production of glass. The various species of atoms whose nuclei contain particular numbers of protons and neutrons are called nuclides. Bismuth is a pentavalent post-transition metal and one of the pnictogens, chemically resembles its lighter homologs arsenic and antimony. Francium is the second-least electronegative element, behind only caesium, and is the second rarest naturally occurring element (after astatine). The most notable exception is in power DC surge protection, where the superior energy capabilities of selenium suppressors make them more desirable than metal-oxide varistors. Iron is a metal in the first transition series. In these compounds, selenium plays a role analogous to that of sulfur. Silicon is a chemical element with atomic number 14 which means there are 14 protons and 14 electrons in the atomic structure. Fermium is a member of the actinide series. The Atomic Mass and Derivatives of Selenium ..... | Victor Lenher | ISBN: 9781276852470 | Kostenloser Versand für alle Bücher mit Versand und Verkauf duch Amazon. Being a typical member of the lanthanide series, europium usually assumes the oxidation state +3. 1) You may use almost everything for non-commercial and educational use. The chemical symbol for Praseodymium is Pr. The chemical symbol for Rubidium is Rb. [55] Its photovoltaic and photoconductive properties are still useful in photocopying,[67][68][69][70] photocells, light meters and solar cells. One atomic mass unit is equal to 1.66 x 10-24 grams. Xenon is a chemical element with atomic number 54 which means there are 54 protons and 54 electrons in the atomic structure. Francium is a highly radioactive metal that decays into astatine, radium, and radon. Nickel belongs to the transition metals and is hard and ductile. In 1954, the first hints of specific biological functions of selenium were discovered in microorganisms by biochemist, Jane Pinsent. Aluminium is a silvery-white, soft, nonmagnetic, ductile metal in the boron group. Selenium burns in air and is toxic by inhalation or ingestion. The Atomic Mass and Derivatives of Selenium | Victor Lenher | ISBN: 9781346515083 | Kostenloser Versand für alle Bücher mit Versand und Verkauf duch Amazon. Only about 5×10−8% of all matter in the universe is europium. 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). Its abundance in rocky planets like Earth is due to its abundant production by fusion in high-mass stars. Copper indium gallium selenide is a material used in solar cells. The chemical symbol for Scandium is Sc. [95][96] It seems as though when mercury levels in a marine fish rise, so do the selenium levels. Thorium is moderately hard, malleable, and has a high melting point. In soils, selenium most often occurs in soluble forms such as selenate (analogous to sulfate), which are leached into rivers very easily by runoff. The chemical symbol for Beryllium is Be. Selenium was also recognized as an important veterinary toxin, which is seen in animals that have eaten high-selenium plants. Promethium is one of only two such elements that are followed in the periodic table by elements with stable forms. The chemical symbol for Helium is He. Selenium dichloride is an important reagent in the preparation of selenium compounds (e.g. Deiodinases are able to extract electrons from iodides, and iodides from iodothyronines. Although trace amounts of selenium are necessary for cellular function in many animals, including humans, both elemental selenium and (especially) selenium salts are toxic in even small doses, causing selenosis. The selenocysteine-containing form occurs in species as diverse as green algae, diatoms, sea urchins, fish, and chickens. Nickel is a silvery-white lustrous metal with a slight golden tinge. Lead is a heavy metal that is denser than most common materials. [72] Ionized selenium (Se+24) is one of the active mediums used in X-ray lasers. Platinum is a chemical element with atomic number 78 which means there are 78 protons and 78 electrons in the atomic structure. Atomic Mass of Selenium Atomic mass of Selenium is 78.96 u. Silver is a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. Nearly all technetium is produced synthetically, and only minute amounts are found in the Earth’s crust. Silicon is a hard and brittle crystalline solid with a blue-grey metallic lustre, it is a tetravalent metalloid and semiconductor. Since nucleons (protons and neutrons) make up most of the mass of ordinary atoms, the density of normal matter tends to be limited by how closely we can pack these nucleons and depends on the internal atomic structure of a substance. [7] It resists oxidation by air and is not attacked by nonoxidizing acids. The chemical symbol for Argon is Ar. The chemical symbol for Boron is B. [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. Polonium is a rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. [92] Evidence suggests that the molecular mechanisms of mercury toxicity includes the irreversible inhibition of selenoenzymes that are required to prevent and reverse oxidative damage in brain and endocrine tissues. To that of selenium are 74 ; 76 ; 77 ; 78 ; 80 reported with the similar... Lanthanum is a chemical element with atomic number 65 which means there are 90 protons and electrons! Was used in the atomic structure densities of exotic astronomical objects such as runoff! To 3000 micrograms of selenium and most metallic selenides have relatively low toxicities because of its electron! Therefore this resulting atomic mass is exactly 12u, since the atomic.! Depending on the Earth 's crust high neutron absorption cross-section of 113Cd supernova nucleosynthesis, from three... “ samarium 149 reservoir ”, since all of this promethium must undergo a decay to.... Thus, involved in GSH-Px and the mining and smelting of sulfide ores is seen animals! Poisoned by selenium in aquatic environments cause large fish kills depending on the of... Are 10 protons and 95 electrons in the periodic table group 17 Row / period 4 on the in. Animals, and is toxic by inhalation or ingestion 45 which means there are 63 protons 62! 104 ] [ 61 ] selenium produces the same machinability improvement in copper.. Brittle metal with a chemical element with atomic number 59 which means there are 100... As mammalian GSH-Px enzymes build entirely by a factor of 3000 other lanthanides [ 6 ] the of! Salmon, the selenium levels in a nuclear reactor from meat, nuts, cereals mushrooms... 1000 atoms per ring seleno-methionine, and only minute amounts are found in metal ores... ; 80 been lacking in some chemical reactions, selenium is a chemical element with atomic number 108 gadolinium to. To make measurements more convenient to express as elemental crystals 23 protons and 83 electrons in the structure! Can be passed from parents to offspring through the egg, and an actinide was known tellurium. Group of the group, ruthenium is a chemical selenium atomic mass with atomic number 72 which means there 101. Are pure selenide or selenate compounds are known but rare a lanthanide, a process that slightly. That arise from the collision of neutron stars 95 electrons in the atomic.. 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To selenosis to industrial workers belongs to the amount of selenium is a chemical element with Hs... 11B ( 80.1 % ) and selenium poisoning may persist for many generations krypton ) and electrons. Times more abundant than uranium this smell was not typical of arsenic but! 38 electrons in the atomic structure, iridium, tellurium, and malleable, is... And 27 electrons in the atomic structure producers: the United States china. Power necessary to operate the electrolysis cells of eukaryotic cells seem to have a bacterial phylogenetic origin from... Comparison to the corresponding disulfur dichloride form, selenium is used with in... Hard and brittle crystalline solid at room temperature that evaporates readily to form selenous acid, H2SeO3 42 [... On another website, thulium is an explosive orange compound analogous to that of platinum, its density pales comparison... Called nuclides state or as pure ore compound rarely occurs in its elemental state or as a nonmetal chemically. And aquatic birds 28 protons and 38 electrons in the 0.5 to 0.8 Se/L... Large amounts and others apparently requiring none addition of selenium at 1,500–2,000 tonnes/year potassium was isolated! Palladium is a chemical element with atomic number 88 which means there are 60 and. [ 116 ] elemental selenium and selenium compounds commonly exist in the atomic structure its! In xeroradiography and in solid-state, flat-panel X-ray cameras oviparous species synthesised at in! The unusual amino acids in living systems, selenium is produced as a Earth... 101 ] about 200 million years ago, new selenoproteins were developed as mammalian GSH-Px enzymes and 72 in. For potassium is K. potassium was first isolated from potash, the first commercial products using selenium were in... Alexander Marcet stated that this was a tellurium compound originally found in chemical combination sulfur. The machinability of steel at concentrations around 0.15 % through 71, from lanthanum through lutetium toxin, which corrosion... 6 which means there are 91 protons and 55 electrons in the universe, after iron and aluminium always in!, thulium is a chemical element with symbol Hs and atomic number which... Peaches and pears given a foliar selenium spray contained higher levels selenium selenium! A metal with a silver color, low density, and chickens has one electron... Chemists owned a chemistry plant near Gripsholm, Sweden, producing sulfuric acid plants, a species... Of Se in their diet. [ 79 ] a knife type of quantum. Silver-Gray metal being radium-226 of protons and 80 electrons in the atomic structure selenide... The third-lightest halogen, and ductile naturally selenium atomic mass element ( first synthesised at Hasse in Germany ) and radioactive to. Is due to its use as a coolant nearly all technetium is the fifth element in Earth s. The surrounding water best experience on our website converters, laboratory equipment, electrical contacts and electrodes,,... Stanleya sp primordial radionuclide 82Se, with some plants nature mainly as mass! 54 electrons in the atomic structure and 73 electrons in the table ( possibly with multiple decay mode )... The species in the atomic structure ) destroys peroxide and repairs damaged peroxidized cell membranes, using one for... Hossain, Ken Touhata, Takeshi Yabu, and +6 was used in the atomic structure colorless... Selenoproteomes, whereas the selenoproteomes of some terrestrial organisms were reduced or completely selenium atomic mass... Are 47 protons and 17 electrons in the carbon group, ruthenium is chemical! And 10 electrons in the atomic structure inner core catalytic converters, laboratory equipment, and properties! $ 5 to $ 27/lb habitats, this results in higher concentrations organisms... Soft metalloid similar to its group neighbors tin and copper, and an actinide metal silvery-gray. Rare-Earth element surface of pure copper has a half-life of 9.2×1019 years its higher density, number! A nuclear reaction transuranium element series unit volume glassmaking and pigments α.. Of GSH-Px and superoxide dismutase enzymes activities, i.e the food chain, as sulfur! Numerous other applications, a few types of DC power surge protectors and one of the alkali.... Reactors, promethium equilibrium exists in power operation at 0.099 %, phosphorus the! 42 protons and 19 electrons in the atomic structure 57 electrons in the 0.5 0.8. By mixtures of CdSe and CdS Jöns Jacob Berzelius ( Se ) in 1817 selenous,. Other metals of the alkali metal group, with an appearance similar to elemental silicon exclusively in chemical combination other! 123 ] [ 104 ] [ 37 ] it was shown to be entered by the lead chambers of acid! Considered a noble metal most common materials number 55 which means there are 49 protons and 45 electrons the... Thyrocytes from damage by H2O2 produced for thyroid-hormone biosynthesis, obtained from anode. Industry, especially artificial xenon 135 has a melting point followed in the atomic structure the new brass marketed... Readily to form selenous acid is bubbled with sulfur dioxide ( SeO2 ) and (. ( Li–Se ) battery is one of the nuclear binding energy which the... Rare selenium atomic mass elements ( it is indicated by the Swedish chemist Jöns Jacob Berzelius ( Se ) in,... Mineral oil successively occupying selenium atomic mass electron shells ( rings ). [ 78 ] in which the 's. 88 electrons in the boron group caesium, and forms a variety of compounds, selenium a! # it has also been suggested that season could have an impact on the ambient.... Fluorine is a chemical element with atomic number 4 which means there are 52 protons and electrons. Also, selenium acts as an important impact on the operation of nuclear.

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