 Try this one. OK, so this is a nuclear binding energy problem. This one in particular says the atomic mass of F4A19 is 18.9984 AMU. Calculate the nuclear binding energy of this nucleus, the corresponding nuclear binding energy per nucleon, and the nuclear binding energy for a mole of fluorine 19M. So let's attempt to do this one together. So the first thing, hopefully, that you remember you need to do, well, I guess the first thing I would do is remind myself what equation I'm going to use. OK, and that's going to be, of course, Einstein's equation that equals mc squared. So in this case, we're saying delta b equals the mass difference times c squared. Remember, c is a constant, a speed of light constant that's given to you 3.00 times 10 to the 8 meters per second. Well, how do we find delta m? Does that's what we need to look for before we find delta e? Delta e would be the amount of energy that's given off in this nuclear reaction. So the binding energy would be the negative of that. So we need to find that delta e first. Well, before we find that, we have to find the delta m. How do we do that? Well, we have the mass of F19, but we need to figure out what is the mass of the total number of nucleons. Does everybody follow me? Yeah, this one? OK, cool. So the mass of the total number of nucleons is going to be, well, the total number of neutrons plus the total number of protons times their masses. So if we have fluorine 19, every fluorine atom has how many protons in it? Nine protons. So we say nine times the mass of a proton. 1.007825, and plus, well, this is fluorine 19. So it has how many neutrons? 10, OK? So we're going to have to multiply 10 times the mass of one neutron. 1.008655 AMU, OK? So from there, we can get the total mass of the nucleons put together, OK? So try this while I'm doing it, and make sure you guys are getting the same answers. OK, so when I do that to 666, after the decimal, I get 19.156975 AMU, OK? So that's the mass of the total number of nucleons. The mass difference is going to be, well, the mass of the fluorine 19 atom minus the mass of the total number of nucleons, OK? So do we have both of those numbers? Yes and yes. So let's plug in. So 18.9984 AMU minus 19.156975 AMU. What is that noise? It's that metal, huh? So is everybody following me to here? OK, so what we're going to do, so eventually, remember, energy has to be in joules, OK? So if you recall, hopefully you do, this is not going to be given to you on the test. 1 joule equals 1 kilogram meter squared per second squared, OK? So what we're going to get is a mass here in AMU, but we're going to have to convert that to kilograms, OK? So let's get the AMU value first and then figure out what we've got in kilograms. So 18.9984 minus that answer. So the 4 after the decimal is going to be negative 0.1586 AMU. And you don't have to remember this. This will be given to you. But 1 AMU equals 1.661 times 10 to the negative 24th grams. So from here, we can figure out grams, 1,000 grams, you have 1 kilogram, OK? So AMU cancel, cancel. So 1.661 divided by 1,000. So we get the 466 negative 2.634 times 10 to the negative 28 kilograms, OK? So does everybody follow me to that point? I have a wonderful one. You guys got those answers, hopefully, right, when you're calculating. So I'm going to just write down here the change for the difference in mass, negative 2.634 times 10 to the negative 28 kilograms. And that way, I can erase. Does everybody have all this stuff I can erase? Next thing's next, let's plug into our E equals MC squared equation. So delta E equals delta MC squared. We've got delta M over here, negative 2.634 times 10 to the negative 28 kilograms times 3.00 times 10 to the 8 meters per second squared. So this delta E is the delta E for 1, flouring 19 F, OK? Because that's all we've calculated. It's just the 1 F, OK? So that's what we're going to figure out first. So let's calculate this energy. So 3 squared of that. And I get to, what, 4 6 2s? The energy per atom. And this is the energy given off. 1 squared per second squared is joules, OK? Like that. So this is joules, flouring 19 atom. Is everybody OK with that? So the number of nucleons is going to be the number of neutrons plus the number of protons, OK? So how many nucleons does flouring 19 have? Everybody? 19. 19, right? 19. So the number of nucleons, we can say, the number of nucleons like that is 19. So let's figure out, well, here. Let's do the, that's the energy released. Let's figure out what's the binding energy for 1 atom first, OK? So the binding energy is just going to be this times minus 1, OK? So the binding energy is going to be the opposite of the energy released. Is everybody OK with that? So it's going to be the binding energy for 1 F 19 atom. It's going to be 2.371 times 10 to the negative 11 joules per 1 fluorine 19 atom. And what did we say? For every 1 fluorine 19 atom, we have 19 nucleons, right? So are you OK with what I've just done there? Yes. OK. So the number of nucleons is going to be the number of nucleons plus the number of neutrons plus the number of neutrons plus the number of neutrons plus the number of neutrons in there. OK. So we're going to divide that number by 19. So per nucleon, I get, again, 4 sick bigs, 1.248 times 10 to the negative 12 joules per nucleon. Is everybody OK with what I've done there? Yes. OK, cool. So the last thing it wants us to do is figure out, well, how many joules per mole of fluorine 19 atoms, OK? So, well, what conversion factor do I need to know to do that? 1 mole equals 6.022 times 10 to the 23rd, in this case, atoms, right? OK, so we'll say the binding energy of a mole of fluorine 19. Is everybody OK with me writing like that? OK, wonderful. So we're going to use this number here, because that's per 1 atom, right? So 2.371 times 10 to the negative 11 joules per 1 fluorine 19 atom. Well, how many fluorine 19 atoms per mole? 6.022 times 10 to the 23rd fluorine atoms per 1 mole of F 19. Like that? Is everybody OK with that one? Yes. So cancel, cancel like that. And then why don't we go all the way up to kilojoules, because it's going to be a big number, OK? So for every 1,000 joules, we have one kilojoule. So we'll cancel our joules out, and that'll give us kilojoules for a 5-point, OK? So going back to 2.37. So we're going to multiply that number by 6.02223, and then divide it by 1,000. And hopefully, everybody gets the same binding energy I do to 4 sick pigs. And that's going to be 1.428 times 10 to the 10 kilojoules per mole. Any questions on something like that? Does it make sense all the units that we got? Yep. Make sure that you guys can do these. I expect these will be the harder problems on this particular portion of the quiz or exam for nuclear chemistry. Questions?