Physlet Illustration: Emission in the Bohr Model



Starting Level=  Ending Level= 
In this simulation, an electron is shown orbiting a proton in the Bohr model for hydrogen.  The user may change the ending level (1 to 3) and the starting level (ending level + 1 to ending level +4).  After a short time, the electron "drops" to a lower level, giving off a photon.  The line spectrum is shown below.  How does the wavelength of the emitted photon depend on the starting and ending orbital levels?


  1. Keeping the ending level at 2, try different starting orbits.  What happens to the wavelength of the photon when the difference is small?  When it is large?
  2. Set the ending level to 1 and try different starting orbits.  What is different now?
  3. Try setting the ending level to 3.  What is different in this case?
  4. Which of these corresponds to the Paschen series?  The Balmer series? 


See Walker, Sections 31-3

Illustration written by Mario Belloni and Chuck Niederriter