Thanks for the video. I just had a question- at 21:01 you said it is the "sixth energy level" and there are 6 complete wave cycles. In the Paul Hewitt diagram, it shows one wavelength for the first energy level, 2 for the second, 3 for the third, etc. So can n be any integer (e.g. could there be 3 wavelengths in the second energy level) or does there always have to be n complete wavelengths in the nth energy level?
I have a question on the electron in box MCQ at 17:11. In the hydrogen emission spectra, we learnt that the energy levels converge as they increase, so how does this fit with that?
Hi, your videos are very helpful, but I think one part of the syllabus, tunnelling was not includes as a part of the videos. Can you please give a general explanation of tunnelling?
If say we have a marble in a bowl, it will not escape the bowl unless it is given enough kinetic energy, however, in quantum mechanics, there is a possibility that say an electron in a potential well, could be found outside of the well. This is very important in alpha decay, light emitting diodes, supercomputers etc. So alpha decay could not occur without the alpha particle escaping a potential energy trap that it does not have enough energy classically to do so. This video was made before the latest syllabus so it did not include tunneling.
There's one problem with the analogy you used when explaining probability in a standing wave. The wave function is a complex function, so when you square the standing wave you only see the probability at the nodes to be zero because you're not on a complex plane, but that doesn't mean that there's zero probability of finding electrons there.
The challenge always facing me is to explain in terms of concepts that the students already have some understanding of. Should I introduce complex functions?
Perhaps a mention would've been informative. Don't get me wrong, your videos are absolutely awesome and they help me a lot! I just think complex numbers are not out of the scope since we're talking about wavefunctions here and the IB syllabus does introduce complex numbers.
+Chris Doner (C. Doner's IB Physics) It is in the old booklet (2009 version). I cannot find it in the 2016 one. Do i use a wrong booklet? : schools.cms.k12.nc.us/myersparkHS/Documents/Physics%20Data%20Booklet.pdf
This was really helpful and incredibly well explained! Thank you so much! :D
Thanks for the video. I just had a question- at 21:01 you said it is the "sixth energy level" and there are 6 complete wave cycles. In the Paul Hewitt diagram, it shows one wavelength for the first energy level, 2 for the second, 3 for the third, etc. So can n be any integer (e.g. could there be 3 wavelengths in the second energy level) or does there always have to be n complete wavelengths in the nth energy level?
The nth energy level would fit n wavelengths.
@@donerphysics Alright, thank you
I have a question on the electron in box MCQ at 17:11. In the hydrogen emission spectra, we learnt that the energy levels converge as they increase, so how does this fit with that?
They are quite different. One has two potentials acting as walls, and the other has a single potential.
In 24:27 how did you get the denominator on the right as 2mr^2?
Multiply numerator and denominator by mr^2
Please what is the magnitude of(L)
Is this still in the new syllabus? I'm M23 doing my final revision but I have not seen this before...
This is more detailed than you need. You simply need to understand what a wavefunction describes and how it relates to tunneling.
@@donerphysics OK thanks!
Hello, why is does an electron orbiting around a nucleus does not have electric potential energy? There would be a field created by the nucleus...
It does have PE.
Hi, your videos are very helpful, but I think one part of the syllabus, tunnelling was not includes as a part of the videos. Can you please give a general explanation of tunnelling?
If say we have a marble in a bowl, it will not escape the bowl unless it is given enough kinetic energy, however, in quantum mechanics, there is a possibility that say an electron in a potential well, could be found outside of the well. This is very important in alpha decay, light emitting diodes, supercomputers etc. So alpha decay could not occur without the alpha particle escaping a potential energy trap that it does not have enough energy classically to do so. This video was made before the latest syllabus so it did not include tunneling.
he is the messiah
I am not the messiah! (from Monty Python)
Mr. Doner, how did you convert eV from joules during the proving En=-13.6/(n^2) to be true again? At 24:30?
One electronvolt = 1.6 x 10^-19 Joules. It is called an electronvolt because it is the energy acquired by an electron when accelerated through 1 volt.
Chris Doner thank you sir.
There's one problem with the analogy you used when explaining probability in a standing wave. The wave function is a complex function, so when you square the standing wave you only see the probability at the nodes to be zero because you're not on a complex plane, but that doesn't mean that there's zero probability of finding electrons there.
The challenge always facing me is to explain in terms of concepts that the students already have some understanding of. Should I introduce complex functions?
Perhaps a mention would've been informative. Don't get me wrong, your videos are absolutely awesome and they help me a lot! I just think complex numbers are not out of the scope since we're talking about wavefunctions here and the IB syllabus does introduce complex numbers.
It is great that you brought it up because now it is mentioned. Thank you!
Mr. Doner, am i supposed to remember the electron in a box formula? (for the IB exam)
+Aren Karapetyan
It is in the data booklet...know the booklet well!
+Chris Doner (C. Doner's IB Physics) It is in the old booklet (2009 version). I cannot find it in the 2016 one. Do i use a wrong booklet? : schools.cms.k12.nc.us/myersparkHS/Documents/Physics%20Data%20Booklet.pdf
+Aren Karapetyan
Electron in a box has been taken out of the new syllabus. Don't worry about it. I have not finished updating the HL topics.
+Chris Doner (C. Doner's IB Physics) Ok, thanks very much