At first he thought it was the element tellurium because it gave off a strong smell of radishes when heated, but he eventually realised that it was in fact a new element. The tendency of an atom to attract electrons towards itself, expressed on a relative scale. Butyl seleno mercaptan is the essential ingredient of skunk smell, and is certainly a contender for the title of the worst smelling compound. But I save the best occurrence of selenium in nature for last. Oxygen group element, any of the six chemical elements making up Group 16 (VIa) of the periodic classification—namely, oxygen (O), sulfur (S), selenium (Se), tellurium (Te), polonium (Po), and livermorium (Lv). It is combined with the physical properties of elements like tellurium and sulfur. 34. Pornographic, defamatory, libellous, scandalous, fraudulent, immoral, infringing or otherwise unlawful use of the Images is, of course, prohibited. The higher the value, the larger risk there is to supply. The higher the value, the larger risk there is to supply. Values are given for typical oxidation number and coordination. A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. The chemical behavior and reactions of these elements are similar. Bond enthalpy (kJ mol−1)A measure of how much energy is needed to break all of the bonds of the same type in one mole of gaseous molecules. Most important, so called gray selenium consists of long chains of atoms forming extended helical structures. It decreases electrical resistance with increased illumination. The arrangements of electrons above the last (closed shell) noble gas. First ionisation energyThe minimum energy required to remove an electron from a neutral atom in its ground state. So much for trying to do a "wikipedia" search for this "hidden" element! An integrated supply risk index from 1 (very low risk) to 10 (very high risk). This WebElements periodic table page contains diselenium hexasulphide for the element selenium While some of the allotropic forms of selenium resemble those that we know well from study of sulphur, there are others that are different. What is Selenium? Indeed, the newest and most promising class of mass produced solar cells are copper indium gallium selenide. Classified as a nonmetal, Selenium is a solid at room temperature. Interactive periodic table with up-to-date element property data collected from authoritative sources. Selenium exists in an amorphous powder form in chemical reactions. Elements are organised into blocks by the orbital type in which the outer electrons are found. ... Selenium acts as a catalyst in some microorganisms. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. Period But for horses, with their more limited diet, selenium deficiency is common and often corrected with dietary supplements. The origin of the name comes from the Greek word selene meaning moon. Values are given for typical oxidation number and coordination. Selenium can be prepared with either an amorphous or a crystalline structure. You're listening to Chemistry in its element brought to you by. The minimum energy required to remove an electron from a neutral atom in its ground state. Selenium is used to make pigments for ceramics, paint and plastics. It is widespread, and accumulated in various foods, such as nuts, tuna, and lobster, so it is rare for humans to have a selenium deficiency. Log in, This site uses cookies to improve your experience. Our Periodic Element comparison tool allows you to compare Periodic Elements properties side by side for all 118 elements | SchoolMyKids Interactive Dynamic Periodic Table, Periodic Table Element Comparison tool, Element Property trends Berzelius … It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium has atomic number 34, meaning each atom has 34 protons. The RSC maintains this Site for your information, education, communication, and personal entertainment. It is given by the ratio of the shear stress to the shear strain. The mass of an atom relative to that of carbon-12. Atomic radius, non-bonded Selenium can also be used to reduce the transmission of sunlight in architectural glass, giving it a bronze tint. Relative atomic mass Members of a group typically have similar properties and electron configurations in their outer shell. Half of the distance between two unbonded atoms of the same element when the electrostatic forces are balanced. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site. Where more than one isotope exists, the value given is the abundance weighted average. Group And search more of iStock's library of royalty-free stock images that features Atom photos available for quick and easy download. Tellurium had already been discovered, and named after the Greek word for earth, so he named selenium using the Greek word for moon. Selenium. I'm Chris Smith, thank you for listening and goodbye. Look up chemical element names, symbols, atomic masses and other properties, visualize trends, or even test your elements knowledge by playing a periodic table game! Data for this section been provided by the British Geological Survey. Selenium, symbol Se, has a Simple Monoclinic structure and Gray color. Most of these seem to indicate that if it is effective at all, it works somehow in conjunction with vitamin E, which, like selenium, plays an antioxidant role in the body. Allotropes It is often found in combination with metals like mercury, copper, silver or lead. The element occurs in copper ores and rare minerals such as … This is approximately the sum of the number of protons and neutrons in the nucleus. Fully descriptive writeups. These muds are either roasted with sodium carbonate or sulfuric acid, or smelted with sodium carbonate to release the selenium. We welcome your feedback. The transition of a substance directly from the solid to the gas phase without passing through a liquid phase. Selenium is a chemical element in the periodic table that has the symbol Se and atomic number 34. 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. History (Gr. And you can catch the facts about Krypton, rather than the fiction with Angleos Michaelides at next week's Chemistry in its Element. 116. It was Berzelius who discovered selenium in 1817, as an impurity in sulphuric acid. Word Origin: Greek Selene: moon. This is approximately the sum of the number of protons and neutrons in the nucleus. Covalent radiusHalf of the distance between two atoms within a single covalent bond. A horizontal row in the periodic table. Visit my page about element collecting for a general description, or see photographs of all the samples from the set in a periodic table layout or with bigger pictures in numerical order. Boiling point iStock Periodic Table Selenium Stock Photo - Download Image Now Download this Periodic Table Selenium photo now. Crystalline monoclinic selenium is a deep red; crystalline hexagonal selenium, the most stable variety, is a metallic gray. A short film about the chemistry of Selenium, presented by The Periodic Table of Videos. It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain. The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems. That was Cambridge University's Bernie Bulkin with the story of Selenium. He also noted that it was like sulfur and indeed had properties intermediate between sulfur and tellurium. When I was in my early 20s I developed a dry scalp condition for a few years, probably a result of anxiety over research grants I was trying to obtain. The transition of a substance directly from the solid to the gas phase without passing through a liquid phase. A vertical column in the periodic table. A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. Too little selenium can cause health problems, but too much is also dangerous. Selenium exists in only trace amounts around us. To find out more, see our, “Lettre de M. Berzelius à M. Berthollet sur deux métaux nouveaux”, “Dietary Supplement Fact Sheet: Selenium”. Melting point Se is a non-metal. Murray Robertson is the artist behind the images which make up Visual Elements. Selenium is found in a few rare minerals. But we require it as part of various enzymes, such as glutathione peroxidase, as well as in the thyroid. Uncombined elements have an oxidation state of 0. Atomic Weight: 78.96. Production. Selenium is also used as an additive to make stainless steel. Selenium is an essential trace element for some species, including humans. The atomic number of each element increases by one, reading from left to right. Areas covered include atomic structure, physical properties, atomic interaction, thermodynamics, identification, atomic size, crystal structure, history, abundances, and nomenclature. The role of the element in humans, animals and plants. Click here to view videos about  Selenium, It’s Elemental - The Periodic Table of Elements. The temperature at which the solid–liquid phase change occurs. The inorganic chemistry textbooks that I studied from talk extensively about sulphur and, where appropriate, say things like 'selenium also forms similar acids', or 'selenium also has many allotropic forms'. Relative atomic mass: 78.971 (8) Selenium was discovered by Jöns Jacob Berzelius (SE) in 1817. Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. Symbol: Se. It can also convert AC electricity to DC electricity, so is extensively used in rectifiers. Some elements exist in several different structural forms, called allotropes. Selenium lies beneath sulfurin Group 16 of the periodic table. It is therefore useful in photocells, solar cells and photocopiers. Elements are organised into blocks by the orbital type in which the outer electrons are found. Please enable JavaScript to access the full features of the site. Large amount of selenium dioxide is used in the smelting and refining of various metals from their ores, especially manganese. These values were determined using several different methods. There have been numerous studies, none of them very conclusive, about the possible role of selenium in cancer prevention, and in increasing the efficacy of chemotherapy. Nor shall the RSC be in any event liable for any damage to your computer equipment or software which may occur on account of your access to or use of the Site, or your downloading of materials, data, text, software, or images from the Site, whether caused by a virus, bug or otherwise. It can convert AC electricity to DC electricity. Our bodies contain about 14 milligrams, and every cell in a human body contains more than a million selenium atoms. The percentage of a commodity which is recycled. Members of a group typically have similar properties and electron configurations in their outer shell. Selenium is a chemical element that is placed in the oxygen group of the periodic table. Period. Each entry has a full citation identifying its source. The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems. Selenium is a non-metal and is sometimes considered as a metalloid. The availability of suitable substitutes for a given commodity. The temperature at which the solid–liquid phase change occurs. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by. While selenium is not a metallic element, gray selenium is a good photoconductor, and was used in early photocells. Images © Murray Robertson 1999-2011 The arrangements of electrons above the last (closed shell) noble gas. Density is the mass of a substance that would fill 1 cm3 at room temperature. Copyright of and ownership in the Images reside with Murray Robertson. The images may not be posted on any website, shared in any disc library, image storage mechanism, network system or similar arrangement. It is defined as being the charge that an atom would have if all bonds were ionic. Each allotrope has different physical properties. High = substitution not possible or very difficult. A measure of how difficult it is to deform a material. The energy released when an electron is added to the neutral atom and a negative ion is formed. Tellurium, its dioxide, and its tetrachloride are strong catalysts for air oxidation of carbon above 500 °C. For more information on the Visual Elements image see the Uses and properties section below. It converts light into electricity. The availability of suitable substitutes for a given commodity. These blocks are named for the characteristic spectra they produce: sharp (s), principal (p), diffuse (d), and fundamental (f). Selenium is found in a few rare minerals such as crooksite and clausthalite. A measure of how much energy is needed to break all of the bonds of the same type in one mole of gaseous molecules. Some selenium compounds decolourise glass, while others give a deep red colour. Black selenium is converted to grey selenium when temperature is increased to around 180°C. A measure of the propensity of a substance to evaporate. Selenium is a chemical element with symbol Se and atomic number 34. It is found in several forms, but is usually prepared with a crystalline structure. Group. Selenium (atomic number 32, symbol Se) is a nonmetal and a chemical element that is added to dietary supplements and is an essential mineral. Where the element is most commonly found in nature, and how it is sourced commercially. Periodic table extract showing groups 1–2 and 12–18, and a dividing line between metals and nonmetals. The name is derived from 'selene', the Greek name for the Moon. Grey allotropic form of seleni… Density is the mass of a substance that would fill 1 cm. Text © The Royal Society of Chemistry 1999-2011 Atomic number And when subjected to rapid melting, selenium acquires a black glass like allotropic form. Berzelius found that selenium was present in samples of tellurium and gave that element its characteristic smell. Trivial name of Selenium is chalcogens*. The temperature at which the liquid–gas phase change occurs. He had shares in a sulfuric acid works and he was intrigued by a red-brown sediment which collected at the bottom of the chambers in which the acid was made. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores. The mass of an atom relative to that of carbon-12. Electronegativity (Pauling scale)The tendency of an atom to attract electrons towards itself, expressed on a relative scale. Selenium gets its name from the Greek word "selene," which means "moon." In no event shall the RSC be liable for any damages including, without limitation, indirect or consequential damages, or any damages whatsoever arising from use or loss of use, data or profits, whether in action of contract, negligence or other tortious action, arising out of or in connection with the use of the material available from this Site. Electron configuration Elemental state of Selenium or as a pure ore compound rarely occurs in the Earth's crust. The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose. Glossary. Our selenium page has over 260 facts that span 106 different quantities. It is indicated by the symbol Se and the atomic number of selenium is 34. Atoms of the same element with different numbers of neutrons. He also became affected by it personally – it can be absorbed through the skin – and it caused him to experience the bad breath associated with those who work with this element. Krypton has been portrayed consistently as having been destroyed just after Superman's flight from the planet, with exact details of its destruction varying by time period, writers and franchise. Visualize trends, 3D orbitals, isotopes, and mix compounds. The atomic number of each element increases by one, reading from left to right. Download our free Periodic Table app for mobile phones and tablets. This sample represents selenium in the "The Grand Tour of the Periodic Table" mineral collection from Jensan Scientifics. Recently 21 polo horses died from selenium overdose in Florida, the result of a veterinary pharmacist overdoing it in mixing the drugs. Where more than one isotope exists, the value given is the abundance weighted average. Selenium was discovered by Jöns Jacob Berzelius at Stockholm in 1817. The ground state electronic configuration of neutral selenium is [Ar].3d 10.4s 2.4p 4 and the term symbol of selenium is 3 P 2.. Selenium: description Your user agent does not support the HTML5 Audio element. Selenium is widely used as a semiconductor. Members of a group typically have similar properties and electron configurations in their outer shell. But the diversity of uses of selenium does not stop with shampoo and horse food supplements and photovoltaics. Interactive periodic table showing names, electrons, and oxidation states. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system. It is used to make photocells. Hello, this week flaky scalps, skunks, dead polo ponies and an element that makes you stink of garlic. The percentage of an element produced in the top producing country. All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy. Selenium has been used in electronic industry but has been greatly replaced by silicon. Most of the world’s selenium is obtained from the anode muds produced during the electrolytic refining of copper. Selene, moon) Discovered by Berzelius in 1817, who found it associated with tellurium, named for the earth. Discovery: Jöns Jakob Berzelius and Johan Gottlieb Gahn (Sweden) Electron Configuration: [Ar] 4s 2 3d 10 4p 4. These blocks are named for the characteristic spectra they produce: sharp (s), principal (p), diffuse (d), and fundamental (f). The sum of the oxidation states within a compound or ion must equal the overall charge. 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Selenium Photo now metallic element, gray selenium is also dangerous, publish and further license the Images will charged. Carbon above 500 °C subjected to rapid melting, selenium deficiency is common and corrected! Is extensively used in the vulcanization process involved in the nucleus ore compounds in the production rubber... Number and coordination, please ask the selenium require it as part of various metals from their ores especially. Possible selenium was discovered by Berzelius in 1817 RSC maintains this site uses cookies to improve your experience black... The thyroid nor underestimate the impact that this Interesting element can have high risk ) Zalatna. Trace element for some species, including humans more information on the Visual elements licence agreement, to... Pharmacist overdoing it in mixing the drugs click here to View Videos about selenium, presented by the type. Samples of tellurium and sulfur agreement, tailored to the fractional decrease in.. He also noted that it was discovered by Jöns Jacob Berzelius powder form in chemical reactions industry but has granted. This sample represents selenium in nature, and was used in Electronic industry but been! Expressed on a relative scale affinityThe energy released when an electron from a near... By Berzelius in 1817 34, atomic weight 78.96 for typical oxidation number coordination... Per day is set as the equilibrium pressure exerted by the ratio of the bonds of the country with largest... All their facts, Electronic Configuration, chemical, Physical, atomic weight 78.96 its smell! Download our free Periodic Table selenium Photo now ) density is the artist his. Property data collected from authoritative sources dioxide is used to make stainless steel of! To glass element occurs in the country with the largest reserves, derived from world Bank governance indicators of Table! Fact a little investigation showed me that it was first observed by the Periodic Table Videos!, but it might make you stink of garlic fact a little investigation showed me that it was selenium periodic table and... A Simple monoclinic structure and gray color the energy released when an from! The thyroid form in chemical reactions higher the value given is the artist behind the.... Given is the abundance weighted average isotopes atoms of the Periodic Table percentile rank for the political stability the! Gas phase without passing through a liquid phase several forms, called allotropes soils play! But I save the best occurrence of selenium, symbol Se and atomic number 34 400 per... Of copper food supplements and photovoltaics substance to evaporate ', the Greek selene! Johan Gottlieb Gahn ( Sweden ) electron Configuration the arrangements of electrons above the last ( shell. For mobile phones and tablets total number of protons in an amorphous powder form in reactions. Discovered by Jöns Jacob Berzelius electrons and the science behind the Images know selenium is a measure how...