I Wavefunction of ionized hydrogen electron

Click For Summary
The discussion centers on the ionization of the electron in a hydrogen atom, emphasizing that there is no specific quantum number at which the electron becomes ejected, as there are infinite bound states. As the principal quantum number approaches infinity, the energy remains finite, allowing for the possibility of an unbound state, characterized by a scattering wave function resembling a sine wave at large distances. The conversation also touches on the nature of the wave function during ionization, noting that for energies below 13.6 eV, the wave function is a product of a Laguerre polynomial and a decaying exponential, while above this energy, the solutions behave like sine functions in Cartesian coordinates. Participants express frustration over the lack of effort in understanding the mathematical proofs related to these concepts. Overall, the discussion highlights the complexities of quantum mechanics in relation to ionization and wave functions.
Physicsman88
Messages
5
Reaction score
0
TL;DR
When you solve the schrodinger equation and get the wavefunctions for hydrogen is there a point where the quantum number becomes so high the electron gets ejected and breaks free. If so what would the wave function look like
At what point does the electron become ionized in the hydrogen atom solution
 
Physics news on Phys.org
There is an infinite number of bound states, so no, there is no "point where the quantum number becomes so high the electron gets ejected and breaks free."

That said, even as ##n \rightarrow \infty## the energy remains finite, so it is possible to have an electron no longer bound to the nucleus. Its wave function then looks like a scattering state, which is basically an oscillating sine wave, except close to the nucleus.
 
  • Like
Likes Twigg and Vanadium 50
DrClaude said:
There is an infinite number of bound states, so no, there is no "point where the quantum number becomes so high the electron gets ejected and breaks free."

That said, even as ##n \rightarrow \infty## the energy remains finite, so it is possible to have an electron no longer bound to the nucleus. Its wave function then looks like a scattering state, which is basically an oscillating sine wave, except close to the nucleus.
What happens to the angular component of the wavefunction when the electron gets ionized.
 
DrClaude said:
There is an infinite number of bound states, so no, there is no "point where the quantum number becomes so high the electron gets ejected and breaks free."

That said, even as ##n \rightarrow \infty## the energy remains finite, so it is possible to have an electron no longer bound to the nucleus. Its wave function then looks like a scattering state, which is basically an oscillating sine wave, except close to the nucleus.
How do you show that as n goes to infinity The radial wavefunction becomes a sine wave
 
Physicsman88 said:
What happens to the angular component of the wavefunction when the electron gets ionized.
That depends on how ionization takes place.

Physicsman88 said:
How do you show that as n goes to infinity The radial wavefunction becomes a sine wave
That's not what happens. For E < 13.6 eV, you have an infinite number of bound states with the wave function a product of a Laguerre polynomial and a decaying exponential. For E > 13.6 eV, the solutions are sines as ##r \rightarrow \infty##, like what is obtained for a (finite) square potential, as found in most QM textbooks.
 
  • Like
Likes Twigg
How do you mathematically show that the solutions are sines for the radial wavefunction when E>13.6 eV like is there a proof for it
 
Physicsman88 said:
How do you mathematically show that the solutions are sines for the radial wavefunction when E>13.6 eV like is there a proof for it
Since they aren't, you don't. They are sines for unbound particles in Cartesian coordinates.
 
  • Like
Likes Bystander
Vanadium 50 said:
Since they aren't, you don't. They are sines for unbound particles in Cartesian coordinates.
So if the unbounded radial wavefunctions arent sine waves what are they then
 
Physicsman88 said:
So if the unbounded radial wavefunctions arent sine waves what are they then
My slaves! Solve this equation for me!

Are you going to put in any effort at all? Seriously - if careful reading of replies is too much effort, and Googlinmg "wave equation in spherical coordinates" is too much effort, how do you expect to make any progress? We can't simply pour information into your head.

For an l=0 case, the wavefunction is of the form sin(kr-wt)/r.
 
Last edited:
  • Like
Likes vanhees71
  • #10
The unbound hydrogen states are briefly mentioned on page 231 of these notes.
 
  • Like
Likes DrClaude and vanhees71