When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Cohesion (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Cohesion_(chemistry)

    Mercury in a glass flask is a good example of the effects of the ratio between cohesive and adhesive forces. Because of its high cohesion and low adhesion to the glass, mercury does not spread out to cover the bottom of the flask, and if enough is placed in the flask to cover the bottom, it exhibits a strongly convex meniscus, whereas the ...

  3. Covalent organic framework - Wikipedia

    en.wikipedia.org/wiki/Covalent_organic_framework

    The 3D COF called COF-300 [23] and the 2D COF named TpOMe-DAQ [24] are good examples of this chemistry. When 1,3,5-triformylphloroglucinol (TFP) is used as one of the SBUs, two complementary tautomerizations occur (an enol to keto and an imine to enamine) which result in a β-ketoenamine moiety [ 25 ] as depicted in the DAAQ-TFP [ 26 ] framework.

  4. Molecular descriptor - Wikipedia

    en.wikipedia.org/wiki/Molecular_descriptor

    The invariance properties of molecular descriptors can be defined as the ability of the algorithm for their calculation to give a descriptor value that is independent of the particular characteristics of the molecular representation, such as atom numbering or labeling, spatial reference frame, molecular conformations, etc. Invariance to molecular numbering or labeling is assumed as a minimal ...

  5. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  6. Field effect (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Field_effect_(chemistry)

    A bicycloheptane acid with an electron-withdrawing substituent, X, at the 4-position experiences a field effect on the acidic proton from the C-X bond dipole. [4] A bicyclooctance acid with an electron-witituent, X, at the 4-position experiences the same field effect on the acidic proton from the C-X bondole as the related bicylcoheptane.

  7. Radiofrequency ablation - Wikipedia

    en.wikipedia.org/wiki/Radiofrequency_ablation

    Radiofrequency ablation (RFA), also called fulguration, [1] is a medical procedure in which part of the electrical conduction system of the heart, tumor, sensory nerves or a dysfunctional tissue is ablated using the heat generated from medium frequency alternating current (in the range of 350–500 kHz).

  8. Reactivity–selectivity principle - Wikipedia

    en.wikipedia.org/wiki/Reactivity–selectivity...

    The sulfur radical was found to be more reactive (6*10 8 vs. 1*10 7 M −1.s −1) and less selective (selectivity ratio 76 vs 1200) than the carbon radical. In this case, the effect can be explained by extending the Bell–Evans–Polanyi principle with a factor δ {\displaystyle \delta \,} accounting for transfer of charge from the reactants ...

  9. Allylic strain - Wikipedia

    en.wikipedia.org/wiki/Allylic_strain

    Allylic strain in an olefin. Allylic strain (also known as A 1,3 strain, 1,3-allylic strain, or A-strain) in organic chemistry is a type of strain energy resulting from the interaction between a substituent on one end of an olefin (a synonym for an alkene) with an allylic substituent on the other end. [1]