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  2. Activation energy - Wikipedia

    en.wikipedia.org/wiki/Activation_energy

    More specifically, we can write the Gibbs free energy of activation in terms of enthalpy and entropy of activation: ΔG ‡ = ΔH ‡ − T ΔS ‡. Then, for a unimolecular, one-step reaction, the approximate relationships E a = Δ H ‡ + RT and A = ( k B T / h ) exp(1 + Δ S ‡ / R ) hold.

  3. Electron affinity - Wikipedia

    en.wikipedia.org/wiki/Electron_affinity

    The relation between the two is E ea = −ΔE(attach). However, if the value assigned to E ea is negative, the negative sign implies a reversal of direction, and energy is required to attach an electron. In this case, the electron capture is an endothermic process and the relationship, E ea = −ΔE(attach) is still valid. Negative values ...

  4. Electron affinity (data page) - Wikipedia

    en.wikipedia.org/wiki/Electron_affinity_(data_page)

    Electron affinity can be defined in two equivalent ways. First, as the energy that is released by adding an electron to an isolated gaseous atom. The second (reverse) definition is that electron affinity is the energy required to remove an electron from a singly charged gaseous negative ion.

  5. Standard enthalpy of formation - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_formation

    The downward arrow "electron affinity" shows the negative quantity –EA F, since EA F is usually defined as positive. For ionic compounds, the standard enthalpy of formation is equivalent to the sum of several terms included in the Born–Haber cycle. For example, the formation of lithium fluoride,

  6. Ethyl acetate - Wikipedia

    en.wikipedia.org/wiki/Ethyl_acetate

    Ethyl acetate (systematically ethyl ethanoate, commonly abbreviated EtOAc, ETAC or EA) is the organic compound with the formula CH 3 CO 2 CH 2 CH 3, simplified to C 4 H 8 O 2.This flammable, colorless liquid has a characteristic sweet smell (similar to pear drops) and is used in glues, nail polish removers, and the decaffeination process of tea and coffee.

  7. Chemical symbol - Wikipedia

    en.wikipedia.org/wiki/Chemical_symbol

    Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.

  8. HOMO and LUMO - Wikipedia

    en.wikipedia.org/wiki/HOMO_and_LUMO

    Diagram of the HOMO and LUMO of a molecule. Each circle represents an electron in an orbital; when light of a high enough frequency is absorbed by an electron in the HOMO, it jumps to the LUMO. 3D model of the highest occupied molecular orbital in CO 2 3D model of the lowest unoccupied molecular orbital in CO 2

  9. Energy profile (chemistry) - Wikipedia

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

    In theoretical chemistry, an energy profile is a theoretical representation of a chemical reaction or process as a single energetic pathway as the reactants are transformed into products. This pathway runs along the reaction coordinate , which is a parametric curve that follows the pathway of the reaction and indicates its progress; thus ...