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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 ...
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.
Selones (R 2 C=Se) are the selenium analogues of ketones. They are rare due to their tendency to oligomerize. [11] Diselenobenzoquinone is stable as a metal complex. [12] Selenourea is an example of a stable compound containing a (formal) C=Se bond. Thioselenides (R−Se−S−R), compounds with selenium(II)–sulfur(II) bonds, analogous to ...
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 .
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
Selenium monochloride or diselenium dichloride is an inorganic compound with the formula Se 2 Cl 2. Although a common name for the compound is selenium monochloride, reflecting its empirical formula , IUPAC does not recommend that name, instead preferring the more descriptive diselenium dichloride.
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.
For example, in phosphorus pentafluoride (PF 5), 5 resonance structures can be generated each with four covalent bonds and one ionic bond with greater weight in the structures placing ionic character in the axial bonds, thus satisfying the octet rule and explaining both the observed trigonal bipyramidal molecular geometry and the fact that the ...