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

I Visible light reflection v.s X-Ray reflection

  1. Nov 30, 2016 #1
    I'm a bit new to studying physics so I hope this question doesn't sound off. I already know this

    "Photons are emitted from an atom when an electron transitions from one state to a lower-energy state. The energy of the emitted photon equal to the difference in energy between the two states."

    1. This makes me wonder, if you were somehow able to permanently increase the mass of Protons and Electrons enough(or have an atom with electrons that had huge state differences), would the energy difference in the lower and higher states of the electrons be able to create and reflect X-Rays or photons with greater energy than visible light?

    2. If the size of protons and electrons were large enough would visible light pass through unaltered?
     
  2. jcsd
  3. Nov 30, 2016 #2

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    I don't understand this at all. We can already emit x-ray from atomic transition. Many x-ray sources used in your doctor's office do this.

    The problem of "reflection" is totally different than simply having atoms that have that kind of transition. x-ray "mirrors" is difficult to create not because atoms do not have such a transition. They do. Rather, "mirrors" are solid, bulk material. The phenomenon of "reflection" requires the formation of the solid and the kind of band structure and vibrational modes present in the solid.

    Besides, why can't you simply have Bragg reflection of these x-rays?

    Zz.
     
  4. Nov 30, 2016 #3
    I guess the mystery that i'm wondering about is if elements could exist that transmit visible light 100% due to having an energy level too high to absorb it. Similar to the way radio waves move through walls.
     
  5. Nov 30, 2016 #4

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Similar to radio waves move through walls? You are comparing apples to oranges.

    "Walls" are solid objects (read my first post here). But you want it to behave like atomic energy levels as if they are isolated atoms.

    I can block radio waves with simple metal walls. Yet, the metal atoms still have "energy level too high to absorb" the radio waves.

    But you were originally talking about "reflection". It is even in the title of this thread. Yet, now, you're talking about transmission. This is not "reflection".

    What now? This is going in all directions with no clear boundary.

    Zz.
     
  6. Nov 30, 2016 #5
    Sorry, I think i'll do some more research on my own. I'm finding this all very confusing.
     
  7. Nov 30, 2016 #6

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Welcome to the club.

    Zz.
     
  8. Dec 3, 2016 #7
    The absorption of x-rays does increase a lot when you raise the photon energy above characteristic binding energies - so called absorption edges. This can be used for spectroscopy. You could say that for photon energies below the edge the material is more transparent than for photon energies above the edge.

    The thing with x-rays is that the photon energies are in the range of hundreds or thousands of electron volts, and that all atoms have at least some electrons with much lower binding energy, in the eV or 10 eV range. These can always be excited by x-ray photons. Therefore no material is completely transparent for x-rays.

    However, this concerns transmission, not reflection.

    https://en.wikipedia.org/wiki/X-ray_absorption_spectroscopy
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Visible light reflection v.s X-Ray reflection
  1. Bragg reflections (Replies: 6)

Loading...