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Radiation chemistry is a subdivision of nuclear chemistry which studies the chemical effects of ionizing radiation on matter. This is quite different from radiochemistry, as no radioactivity needs to be present in the material which is being chemically changed by the radiation. An example is the conversion of water into hydrogen gas and ...
In order to study gas phase interstellar chemistry, it is convenient to distinguish two types of interstellar clouds: diffuse clouds, with T=30-100 K, and n=10–1000 cm −3, and dense clouds with T=10-30K and density n= 10 4-10 3 cm −3. Ion chemical routes in both dense and diffuse clouds have been established for some works (Hartquist 1990).
Water subjected to ionizing radiation forms free radicals of hydrogen and hydroxyl, which can recombine to form gaseous hydrogen, oxygen, hydrogen peroxide, hydroxyl radicals, and peroxide radicals. In living organisms, which are composed mostly of water, majority of the damage is caused by the reactive oxygen species , free radicals produced ...
Hydrogen peroxide is not nearly as reactive as these species, but is readily activated and is thus included. [3] Peroxynitrite and nitric oxide are reactive oxygen-containing species as well. Hydroxyl radical ( HO· ) is generated by Fenton reaction of hydrogen peroxide with ferrous compounds and related reducing agents:
Hydrogen peroxide is a chemical compound with the formula H 2 O 2.In its pure form, it is a very pale blue [5] liquid that is slightly more viscous than water.It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concentrations for industrial use.
Radical abstraction between a benzoyloxy radical and hydrogen bromide. Hydrogen abstraction generates radicals. To achieve this reaction, the C-H bond of the H-atom donor must be weak, which is rarely the case in organic compounds. Allylic and especiall doubly allylic C-H bonds are prone to abstraction by O 2.
Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volts (eV), which is enough to ionize atoms and molecules and break chemical bonds. This is an important distinction due to the large difference in harmfulness to living organisms.
Radiolysis is the dissociation of molecules by ionizing radiation.It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux.The radiation in this context is associated with ionizing radiation; radiolysis is therefore distinguished from, for example, photolysis of the Cl 2 molecule into two Cl-radicals, where (ultraviolet or visible spectrum) light is used.