 So the sister problem to that last problem we did, so the last problem is that the electron went from n equals 1 was 5 to n equals 2 was 3, or the energy level 5 to energy level 3. In this case we're going from energy level 3 to energy level 5, so this should be going up in energy, right? So we would expect, like last time we got a negative energy. Hopefully this time you guys would expect us to get a positive energy. And if you want to think about it, remember where the energy levels are in relation to each other. So we think about n equals 1 is there, 2 is there, 3 is there, 4 is there, 5 is there, right? So it takes energy, it's like climbing a ladder, to go from 3 to 5, right? So you can fall without having any energy, in fact you're losing energy if you fall off the ladder, if you want to think about it that way. So anyways we again need to remember the Rieberg equation and I have the Rieberg energy constant up here for you guys. So the Rieberg equation is E, the Rieberg energy equation, E equals R E, 1 over n2 squared minus 1 over n1 squared. And we've already identified n1 and n2 over, so n2 in this case is 5. So again I don't have much room on this particular board so I'd really like to just convert this to a 25. Okay so now hopefully you see, right, we have a smaller number subtracting a bigger number from it. Okay so this overall is going to be a negative number, okay? Multiply that by a negative number, we should get an overall positive number. So positive energy means you're climbing the ladder if you want to think about it that way. So 5 times 10 to the negative. Like we should have expected we would have, right, because we went exactly that far down the ladder last month, right? So we have to go that far up the ladder. Okay, again this is the shortcut way of doing it. You could use Planck's equation and the speed of light equation to get the energy, but using the Rieberg energy equation kind of cuts those two steps out. So let's do one the other way.