Description: Elemental Selenium 25g, 99.999%+, In Display Bottle, USA Shipping. 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 seldom occurs in its elemental state or as pure ore compounds in Earth's crust. Selenium (from Ancient Greek (seln) 'moon') was discovered in 1817 by Jns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth.) Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot. 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. 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 3 deiodinase enzymes. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently not requiring any. Selenium forms several allotropes that interconvert with temperature changes, depending somewhat on the rate of temperature change. When prepared in chemical reactions, selenium is usually an amorphous, brick-red powder. When rapidly melted, it forms the black, vitreous form, usually sold commercially as beads. The structure of black selenium is irregular and complex and consists of polymeric rings with up to 1000 atoms per ring. Black Se is a brittle, lustrous solid that is slightly soluble in CS2 (Carbon Disulfide). 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. For use in your chemistry experiments. This will come in the form of chunks of pure selenium, unless you want it in the form of shot or beads. If you need it in shot or bead form, like in the last picture, let me know and I will send you that instead of broken chunks. The price is the same either way, you just have to let me know which form you want if you don't want what's pictured in the first picture. You will receive: 1 bottle containing 25g+ of Elemental Selenium and it will be in a bag and bubble wrapped and placed in the container like in the pictures. That will be taped shut and sealed with a tamper seal. That will then be bubble wrapped and placed in a box with the appropriate warning labels and taped shut. That will be placed in a blue, bubble wrap padded envelope for extra padding and shipped via USPS First Class Mail with tracking.
Price: 18.95 USD
Location: Salt Lick, Kentucky
End Time: 2024-09-06T10:47:35.000Z
Shipping Cost: 4.75 USD
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All returns accepted: ReturnsNotAccepted
Country/Region of Manufacture: United States
California Prop 65 Warning: N/A
