00:01
In this problem, you are given the energy levels of an atom, and you're asked about what photon energies can be emitted.
00:10
And in problem 39, you're told that you're put into the excited state that has energy and electron volts of minus one.
00:17
You started from the ground state, and they want to know what you would see in admission.
00:24
Remember, when you're in excited states, you don't stay there.
00:27
You go back to the ground state.
00:28
So there's many routes to get back, depending on what states.
00:32
You transition two on the way back, what stops you make in a way.
00:38
So, let's look at the possibilities.
00:41
You go to the minus two state, which then would go to the minus five state, and then back to the ground state.
00:49
That's one route.
00:50
And the energy differences would be one, three, and six.
00:54
So those are possible emission energies.
00:59
Next, we could go back to the minus two state, but then directly, to the ground state, so this is again one, and this would be nine.
01:12
Or we could go to the first excited state minus five, and that is four, and then to the ground state, which is six, or we could just go directly back, and that is ten.
01:29
Now, of all the choices, you're supposed to choose two, four is one of your choices, ten is one of your choices, none of the others are there, so b and c.
01:40
Is the answer.
01:46
Now, in question 40, you're told that you are given from 4 to 9, electron volts is interacting, is being sent to this atom.
02:06
And you want to know what the emissions, which you might get for photons emitted, what energy you may get.
02:11
Now, you're only going to get admission if there's absorption.
02:14
The only way to get absorption from the ground status is to actually take your be able to take yourself with one of these energies to a excited state four minus 10 plus four it's minus six there's no minus six i 10 plus five is minus five so that's a possibility so let me indicate the transition up so this is for the five and all we can do then is go back down so five electron five would be one five electron volts is one of the possibilities okay, so we've four nothing, five we've done.
02:53
Six, minus ten plus six.
02:57
There's no minus four, that's out.
03:00
Minus ten plus seven, there's no minus three, that's out.
03:04
Minus ten plus eight is two.
03:06
Well, that's possible.
03:08
So here we are.
03:10
This one is, so this is for the eight.
03:16
So what can we do here? we can go down to the minus five, so that's giving off three.
03:24
And then five again get back so those are two possibilities and likewise we could just go back down immediately eight so those are our possibilities from absorbing eight electron photon what about nine minus ten plus nine minus one well that's possible too so this is nine okay let me draw and i should have put in let me put in the transition for the eight there's a transition for the 8.
04:03
Here's the transition for the 9.
04:08
Okay, what can we do here? well, we can come all the way back immediately, so that would be 9.
04:22
We could go to minus 2, so that's 1, and then from minus 2 to minus 5, that's 3, and then from minus 5 to minus 10, it's 5, giving off that amount, or we could go to the minus two and then all the way back down immediately so one and then we would have eight or we could go from one we'd go from minus one to minus five so that's four and then back to five this is this part here this part here is exactly the same as question 39 but they changed the bottom energy so it'd be minus 11 it's minus 10 so there is a difference you had to do it, we calculate.
05:13
But it's the same process.
05:14
Same exact process.
05:17
There were four distinct pathways back in question 39, and there's four distinct pathways back here.
05:24
Now, so that's nine.
05:27
And any fractional one in 4 .5, there's no, these are the energy levels.
05:32
There's minus 10, you know, plus 4 .5.
05:36
There's no, not there either.
05:37
So we don't have to worry about those...