00:01
In this exercise, we have a hydrogen atom that has some internal transition, and because of the transition, it emits a photon with a wavelength equals to 656 nanometers.
00:16
And we want to know from what initial energy level and y to what final energy level and f the atom transition.
00:29
So in order to calculate that, the first thing i'm going to do is to calculate the energy of the photon.
00:37
So the energy of the photon is hc over lambda.
00:40
Hc is 12040 electron volts nanometers.
00:45
And lambda is 656 nanometers.
00:50
So the energy is 1 .89 electron volts.
00:55
Okay, that's the energy of a single photon.
00:59
And by conservation of energy, we know that the energy of the photon plus the energy of the final energy level and e and f of the hydrogen atom is equal to the initial energy of the system, which is just the energy of the initial energy level, e and i.
01:24
So we have that the energy of the photon is just e &i minus e and f.
01:32
So what we have to do now is to calculate the energy of some energy levels of the hydrogen atom and see for which n -i and n -f we have that the quantity e -n -i minus e -n -f is equal to the energy of the photon, which is 1 .89 electron volts.
01:56
So that's what i'm going to do.
01:57
I'm going to calculate first the energy of several, at least some energy levels of the hydrogen atom.
02:07
And then i'm going to try to see which ones fit this equation that's highlighted in blue here...