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Ionizing photons

  1. Jan 4, 2016 #1
    This is my first time on this forum and my knowledge may be a bit basic but I was wondering how does the photoelectric effect in the ionization of atoms differ from the photoelectric effect that makes mirrors reflect. They both have incoming photons that give their energy to electrons which move to a higher energy state and yet one ionizes but the other reflects. Is it because in ionizing the ionizing wavelengths has more energy as E=hf so they completely liberate the electrons whereas other wavelengths lack that energy? Thanks.
  2. jcsd
  3. Jan 4, 2016 #2


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    This is not correct. In reflection, the incoming photon does not move electrons in the reflecting material to a higher energy state. It is perfectly possible to build mirrors that reflect very low energy photons (like radio frequency) that have energies far too low to move electrons to a higher energy state. Reflection can be understood completely classically by considering a classical EM wave incident on a conducting material. The Feynman Lectures on Physics, Vol2 Chapter 33 has a good explanation of refection.
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