1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Hydrogen atom

  1. Apr 11, 2006 #1
    Hey everyone,
    I have a practice problem that I can't figure out:

    A hydrogen atom is initially at rest and in the n=2 state. Subsequently, it decays to the ground state by emitting a photon. What is the speed of the recoiling atom afterwards? (Mass of H atom = 1.67 * 10^-27 kg)

    My approach is to find the difference in energy between the two states by using E = -13.6/n^2 for each state (n=1 and n=2), then finding the energy difference, and setting that equal to (1/2)mv^2 and solving for v, but I'm not getting the right answer. (The correct answer is 3.4 m/s)
    Can someone help me with this?

    Thanks in advance

    -s
     
  2. jcsd
  3. Apr 11, 2006 #2
    use 4 in work reverse?
     
  4. Apr 11, 2006 #3

    dav2008

    User Avatar
    Gold Member

    I would use conservation of momentum.
     
  5. Apr 12, 2006 #4
    Using conservation of momentum solved the problem, thanks.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Hydrogen atom
  1. Hydrogen atom (Replies: 1)

Loading...