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  2. Chemical decomposition - Wikipedia

    en.wikipedia.org/wiki/Chemical_decomposition

    Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. [1] Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis .

  3. Photodissociation - Wikipedia

    en.wikipedia.org/wiki/Photodissociation

    In order to repeat the reaction, the electron in the reaction center needs to be replenished. This occurs by oxidation of water in the case of oxygenic photosynthesis. The electron-deficient reaction center of photosystem II (P680*) is the strongest biological oxidizing agent yet discovered, which allows it to break apart molecules as stable as ...

  4. Norrish reaction - Wikipedia

    en.wikipedia.org/wiki/Norrish_reaction

    A Norrish type II reaction is the photochemical intramolecular abstraction of a γ-hydrogen (a hydrogen atom three carbon positions removed from the carbonyl group) by the excited carbonyl compound to produce a 1,4-biradical as a primary photoproduct. [9] Norrish first reported the reaction in 1937. [10] Norrish type II reaction

  5. Photocatalysis - Wikipedia

    en.wikipedia.org/wiki/Photocatalysis

    In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a photocatalyst, the excited state of which "repeatedly interacts with the reaction partners forming reaction intermediates and regenerates itself after each cycle of such interactions."

  6. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    The flow of energy in an ecosystem is an open system; the Sun constantly gives the planet energy in the form of light while it is eventually used and lost in the form of heat throughout the trophic levels of a food web. Carbon is used to make carbohydrates, fats, and proteins, the major sources of food energy. These compounds are oxidized to ...

  7. Shapiro reaction - Wikipedia

    en.wikipedia.org/wiki/Shapiro_reaction

    The Shapiro reaction or tosylhydrazone decomposition is an organic reaction in which a ketone or aldehyde is converted to an alkene through an intermediate hydrazone in the presence of 2 equivalents of organolithium reagent. [1] [2] [3] The reaction was discovered by Robert H. Shapiro in 1967. [4]

  8. Photodisintegration - Wikipedia

    en.wikipedia.org/wiki/Photodisintegration

    The energy of these rays is sometimes sufficient to start photonuclear reactions resulting in emitted neutrons. One such reaction, 14 7 N (γ,n) 13 7 N, is the only natural process other than those induced by cosmic rays in which 13 7 N is produced on Earth. The unstable isotopes remaining from the reaction may subsequently emit positrons by β ...

  9. Unimolecular ion decomposition - Wikipedia

    en.wikipedia.org/wiki/Unimolecular_ion_decomposition

    Unimolecular ion decomposition is the fragmentation of a gas phase ion in a reaction with a molecularity of one. [1] Ions with sufficient internal energy may fragment in a mass spectrometer, which in some cases may degrade the mass spectrometer performance, but in other cases, such as tandem mass spectrometry, the fragmentation can reveal information about the structure of the ion.