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Selenium forms two oxides: selenium dioxide (SeO 2) and selenium trioxide (SeO 3). Selenium dioxide is formed by the reaction of elemental selenium with oxygen: [5] + It is a polymeric solid that forms monomeric SeO 2 molecules in the gas phase. It dissolves in water to form selenous acid, H 2 SeO 3.
Selenium hexafluoride is the inorganic compound with the formula SeF 6. It is a very toxic colourless gas described as having a "repulsive" odor. [ 5 ] It is not widely encountered and has no commercial applications.
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 ...
[1] [2] [3] Selenium belongs with oxygen and sulfur to the group 16 elements or chalcogens, and similarities in chemistry are to be expected. Organoselenium compounds are found at trace levels in ambient waters, soils and sediments. [4] Selenium can exist with oxidation state −2, +2, +4, +6. Se(II) is the dominant form in organoselenium ...
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.
Salt-like hydride selenides may be formed by heating selenium with a metal hydride in an oxygen-free capsule. For rare earth elements, this method works as long as selenium has enough oxidising power to convert a +2 oxidation state to a +3 state. So for europium and ytterbium it does not work as the monoselenide is more stable. [1]
Rubidium selenide is an inorganic compound composed of selenium and rubidium. It is a selenide with a chemical formula of Rb 2 Se. Rubidium selenide is used together with caesium selenide in photovoltaic cells .
Selenite refers to the anion with the chemical formula Se O 2− 3. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, SO 2− 3. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite Na 2 SeO 3 which is a common ...