When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Selenium - Wikipedia

    en.wikipedia.org/wiki/Selenium

    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.

  3. Jefimenko's equations - Wikipedia

    en.wikipedia.org/wiki/Jefimenko's_equations

    The Heaviside–Feynman formula, also known as the Jefimenko–Feynman formula, can be seen as the point-like electric charge version of Jefimenko's equations. Actually, it can be (non trivially) deduced from them using Dirac functions , or using the Liénard-Wiechert potentials . [ 4 ]

  4. Selenium compounds - Wikipedia

    en.wikipedia.org/wiki/Selenium_compounds

    The sulfoxide in sulfur chemistry is represented in selenium chemistry by the selenoxides (formula RSe(O)R), which are intermediates in organic synthesis, as illustrated by the selenoxide elimination reaction. Consistent with trends indicated by the double bond rule, selenoketones, R(C=Se)R, and selenaldehydes, R(C=Se)H, are rarely observed.

  5. Selenoxide elimination - Wikipedia

    en.wikipedia.org/wiki/Selenoxide_elimination

    Analogous sulfoxide eliminations are generally harder to implement than selenoxide eliminations. Formation of the carbon–sulfur bond is usually accomplished with highly reactive sulfenyl chlorides, which must be prepared for immediate use. However, sulfoxides are more stable than the corresponding selenoxides, and elimination is usually ...

  6. Lists of physics equations - Wikipedia

    en.wikipedia.org/wiki/Lists_of_physics_equations

    In physics, there are equations in every field to relate physical quantities to each other and perform calculations. Entire handbooks of equations can only summarize most of the full subject, else are highly specialized within a certain field. Physics is derived of formulae only.

  7. Lectures on Theoretical Physics - Wikipedia

    en.wikipedia.org/.../Lectures_on_Theoretical_Physics

    Partielle Differentialgleichungen in der Physik, the sixth and final volume of its series, was published in 1947 by Dieterich'sche Verlagsbuchhandlung while it was translated to English by Ernst G. Straus and published by Academic Press in 1949 under the title Partial Differential Equations in Physics. The book was reviewed by George F. Carrier ...

  8. List of chemistry mnemonics - Wikipedia

    en.wikipedia.org/wiki/List_of_chemistry_mnemonics

    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.

  9. Selenium sulfide - Wikipedia

    en.wikipedia.org/wiki/Selenium_sulfide

    Download as PDF; Printable version; In other projects ... move to sidebar hide. Selenium sulfide can refer to either of the following : Selenium disulfide, SeS 2 ...