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Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.
Selenium compounds are compounds containing the element selenium (Se). Among these compounds, selenium has various oxidation states , the most common ones being −2, +4, and +6. Selenium compounds exist in nature in the form of various minerals, such as clausthalite , guanajuatite , tiemannite , crookesite etc., and can also coexist with ...
At higher pH, selenide forms. Solutions of hydrogen selenide and selenide are oxidized by air to give elemental selenium: 2 SeH − + O 2 → 2 Se + 2 OH −. Most elements form selenides. They sometimes have salt-like properties, e.g. sodium selenide, but most exhibit covalent bonding, e.g. molybdenum diselenide. Their properties are diverse ...
The original synthesis involved the redistribution reaction of selenium dioxide and selenium tetrachloride. Pure selenium oxydichloride autoionizes to a dimer: [4] SeOCl 2 ↔ (SeO) 2 Cl + 3 + Cl −. The SeOCl 2 is generally a labile Lewis acid and solutions of sulfur trioxide in SeOCl 2 likely form [SeOCl] + [SO 3 Cl] − the same way. [5]
The ammonia molecule (NH 3), like the water molecule, is abundant in the universe, being a compound of hydrogen (the simplest and most common element) with another very common element, nitrogen. [51] The possible role of liquid ammonia as an alternative solvent for life is an idea that goes back at least to 1954, when J. B. S. Haldane raised ...
Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. [1] Selenium-containing proteins are produced from inorganic selenium via the intermediacy of selenophosphate (PSeO 3 3 ...
Selenium tetrachloride is the inorganic compound composed with the formula SeCl 4. This compound exists as yellow to white volatile solid. This compound exists as yellow to white volatile solid. It is one of two commonly available selenium chlorides , the other example being selenium monochloride , Se 2 Cl 2 .
Selenium tetrafluoride (Se F 4) is an inorganic compound.It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.