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    I need help in the explanation of Raman Scattering..
    what is the cause of raman (inelastic) scattering?
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    (Original post by franniexo)
    I need help in the explanation of Raman Scattering..
    what is the cause of raman (inelastic) scattering?
    When a photon interacts with matter, it can be absorbed if its of the right frequency, this is the basis of most types of spectroscopy.

    In a scattering process, a high energy photon is absorbed and rapidly another is emitted, this process happens very rapidly, and normally the incident and resultant photons have the same energy (rayleigh scattering).

    When the adsorption happens, the absorbing molecule is momentarily excited to a very high virtual energy level, when the photon is emitted the molecule drops back down to its initial energy level. But sometimes, rather than dropping back down to its original level, the molecule drops to an excited state, and therefore the photon release has less energy (stokes scattering). Or if the molecule was initially excited and drop back to a less excited state, then the photon will have a greater energy than the incident photon (anti stokes scattering).

    Raman spectroscopy can be used to investigate vibrational modes of a molecule (where the molecule can drop to a level either 1 above the initial state or one below, expressed as the selection rule deltaV= +- 1

    It can also be used to investigate rotation levels, now the selection rule is deltaJ = +- 2 (where J is the rotational quantum number of the molecule!
 
 
 
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