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Homework Help: Wavelength, Electron

  1. Mar 7, 2008 #1

    Air

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    I need to make sure my method and the formula I have used is correct. Also, my answer for the wavelength seems slightly dodgy. :uhh:

    1. The problem statement, all variables and given/known data
    An electron recombines with a hole losing 2.6eV of electrical potential energy. Calculate the wavelength of the light emitted.


    2. Relevant equations
    Not given. Equations have to be used ourself.


    3. The attempt at a solution
    [itex]E = \frac{hc}{\lambda}[/itex]

    [itex]\lambda = \frac{hc}{E}[/itex]

    [itex]\lambda = \frac{(6.63 \times 10^{-34})(3.00 \times 10^8)}{2.6}[/itex]

    [itex]\lambda = 7.65 \times 10^{-26}m[/itex]
     
  2. jcsd
  3. Mar 7, 2008 #2

    Dick

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    Put units on things and make sure they match up. You'll want to convert 2.6eV to joules.
     
  4. Mar 7, 2008 #3
    You've found the most high energy photon I've ever heard of! ! ! ! Always check the units, you forgot to convert the energy from eV's to Joules.

    and I see now that dick just recommended the same thing. . .
     
    Last edited: Mar 7, 2008
  5. Mar 7, 2008 #4

    Air

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    How would I change eV's to Joules?
     
  6. Mar 7, 2008 #5

    Dick

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    1eV=1.60217646*10^(-19) joules. That's what google says when I type in 'electron volt', anyway.
     
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