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Absorption of light

  1. Aug 11, 2013 #1
    if objects absorb certain wavelengths and reflect some * which give us its colour*
    how does this actually happen ?
    if a certain substance absorbs red colour because it equals the amount of energy * quanta * needed to excite its electron to the next energy level , then shouldn't the electron get back to its former energy level releasing the same colour it absorbed ? shouldn't this mean that objects that absorbs red colour emit red colour ? and also how does light reflect off something ? does it just bounce back ?
  2. jcsd
  3. Aug 11, 2013 #2


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    Not every photon absorbed will be re-emitted at the same wavelength. An excited molecule will take various decay paths with some probability, aka branching factors. Also, the excited molecule can be de-excited by collisions or other processes.
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