Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Physical properties & threshold frequency

  1. Nov 22, 2009 #1
    What effects do the physical properties (size of atom etc.) of an elemental metal have on the threshold frequency for that metal? I haven't been able to find a correlation between a physical property and the size of the threshold frequency myself; maybe I haven't looked hard enough, or maybe I've misunderstood something.
  2. jcsd
  3. Nov 22, 2009 #2
    By "threshold frequency" do you mean "work function" as in photoelectric effect? In that case, it's the ionization energy/electron affinity/all that stuff based on the "physical property" of charge shielding etc.
  4. Nov 25, 2009 #3
    Thank you for answering. Yes, that is what I mean. Do you know where I can find an article describing how those properties affect the work function? I am finishing a project on quantum mechanics, and this is the only part I need.
  5. Nov 28, 2009 #4
    Well, like I said, it's got a lot to do with the ionization energy and/or electron affinity of the metal. If you think about what you learned in your chemistry classes, ionization energy is the amount of energy needed to remove an electron from the highest occupied orbital. In the photoelectric effect experiment, you're striking a metal with a photon (of a certain energy) and removing its electron. So, if you look up these three things (I'd say start with wikipedia) it should start to make sense.
  6. Nov 28, 2009 #5


    User Avatar
    Science Advisor

    This is a backwards question.
    The physical properties of the material are due to the bonding properties and so forth of the constituent atoms, which in turn is a quantum-mechanical property. The work function is also a quantum mechanical property and related to the bonding etc, but apart from that observation there's no simple relationship between these things.
  7. Nov 28, 2009 #6
    Okay. Thank you both for answering. You have given me something to think about.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook