 that we were finishing up in class. So we had just talked about the Rieberg series, but let's go over this problem. So the Ballmer equation can be extended beyond the visible portion of the electromagnetic spectrum to include lines in the ultraviolet. What is the wavelength in nanometers of ultraviolet light in the Ballmer series? So the Ballmer series is N2 equals 2 corresponding to a value of N1 equals 7. So enter your answer to three signals. So let's go ahead and do this problem. So of course, first you've got to remember the Rieberg equation. So it's going to be 1 over wavelength of R times 1, 2 squared minus 1 over N1. We also know the Rieberg constant and what they give you. That's what they give you. And the 7 meters is divided by 1 meter. So when we do this, so everybody was able to get to there. And then let's just continue along, because I think people had a hard time here. So solve this portion first, and then multiply it by this portion. So let's do that together, multiply that by 1.09. I get this answer, 5, 2 times 10 to the 1, 2, 3, 4, 5, 6. So that's 6. And notice the meters is still down here. So it's still per meter like that. So it's per meter in this. So this gives us 1 over the wavelength. So we want wavelengths. So we're going to take this and flip it over. So take 1 meter and divide it by 2.52 times 10 to the 6. And so wavelength, of course, is going to be 1 meter divided by 2.52 times 10 to the 6. Just take 1 divided by a second answer on my computer. Watch out for that, I mean. 3.97 times 10 to the negative 7. Does everybody cool that? But it says to do it in nanometers. So in order to convert this to nanometers, we've got to remember the conversion factor. So I know I gave it to you guys earlier. So 1 times 10 to the negative 9 meters is 1 nanometer. Of course, well, what do we do that hopefully? You guys don't know when you put it. So are there any questions? So I think what it was was when I was putting the m to the minus 1, I put minus 1. So are there any questions on this problem now? Any questions? Your faces look very confused, OK? So any questions? No? OK, cool. We'll kill it and have a good one, guys.