enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Activation energy - Wikipedia

    en.wikipedia.org/wiki/Activation_energy

    Activation energy can be thought of as the magnitude of the potential barrier (sometimes called the energy barrier) separating minima of the potential energy surface pertaining to the initial and final thermodynamic state. For a chemical reaction to proceed at a reasonable rate, the temperature of the system should be high enough such that ...

  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. 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. 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. Energy profile (chemistry) - Wikipedia

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

    In simplest terms, a potential energy surface or PES is a mathematical or graphical representation of the relation between energy of a molecule and its geometry. The methods for describing the potential energy are broken down into a classical mechanics interpretation (molecular mechanics) and a quantum mechanical interpretation.

  8. Pnictogen - Wikipedia

    en.wikipedia.org/wiki/Pnictogen

    The term "pnicogen" is rarer than the term "pnictogen", and the ratio of academic research papers using "pnictogen" to those using "pnicogen" is 2.5 to 1. [4] It comes from the Greek root πνιγ- (choke, strangle), and thus the word "pnictogen" is also a reference to the Dutch and German names for nitrogen ( stikstof and Stickstoff ...

  9. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the ...