Asked by Akshay
The first line of the Balmer series in Hydrogen atom corresponds to the n=3 to n=2 transition, this line is known as H-alpha line. What would be the selection rule for the n=3 to n=2 transition and corresponding lifetimes.
Answers
Answered by
drwls
The n=3 and n=2 levels of H are degenerate, with different angular "L" momentum orbitals (s, p, d, f etc) having the same energy.
n=2 has L = 0 and 1 states (s and p) , and n=3 has L =0, 1 and 2 states (s, p, and d).
From n=3 to 2, only the transitions d->p, p->s and s->p are allowed. The orbital angular momentum quantum number must change by +/- 1. There are also degeneracies associated with the electrons spin direction.
There is a small amount of relativistic splitting of these states, as explained by Willis Lamb, using quantum electrodynamics developed by Palul Dirac.
I suspect this subject goes well beyond the level of the course that you are taking. I am surprised that they would assign such a problem.
The average radiative lifetime of an electron in the n=3 upper level is 1/(4.41*10^7 s^-1) = 2.27*10^-8 seconds .
This must be obtained by averaging over all allowed transitions, with their degeneracies taken into account. There is no way I can lead you though this calculation.
n=2 has L = 0 and 1 states (s and p) , and n=3 has L =0, 1 and 2 states (s, p, and d).
From n=3 to 2, only the transitions d->p, p->s and s->p are allowed. The orbital angular momentum quantum number must change by +/- 1. There are also degeneracies associated with the electrons spin direction.
There is a small amount of relativistic splitting of these states, as explained by Willis Lamb, using quantum electrodynamics developed by Palul Dirac.
I suspect this subject goes well beyond the level of the course that you are taking. I am surprised that they would assign such a problem.
The average radiative lifetime of an electron in the n=3 upper level is 1/(4.41*10^7 s^-1) = 2.27*10^-8 seconds .
This must be obtained by averaging over all allowed transitions, with their degeneracies taken into account. There is no way I can lead you though this calculation.
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.