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Homework Help: Need help please!

  1. Dec 12, 2004 #1
    Interesting problem. Need help!

    Hey everyone!
    I'm having some trouble with this question and i would really appreciate any help!
    Atoms are bombarded by photons. This causes these atoms to move from ground state to the first excitation state of 4.36 eV. What is the momentum of the photons?
    I understand that the photon must provide the electron with 4.36 eV or 6.99e-19 J of energy in order to move it from its ground state to the first excitation state. What i am unsure of is wether this energy is equal to the total kenetic energy of the photon before. Can the photon not have more energy than this???
    Thanks for any help!!
    Last edited: Dec 12, 2004
  2. jcsd
  3. Dec 12, 2004 #2
    My friend thinks this question doesnt give you enough info. He says the photon could move the electron up to the 1st excited state and still have energy,which would change the momentum.
    Is this correct? Or are we missing something?
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