 Okay, so let's try this long problem, I guess. Consider the samples of pollen compounds and each with a mass of 114 grams rank the compounds from least to greatest number of hydrogen atoms in the sample. Okay, so you could go about this a couple of ways. I guess maybe the first way that I would think about doing this is to figure out what is the molecular weight of each of these compounds. So that would be the first thing I would do. So if we calculate our molecular weights, phosphorus triadide, or fosstream here, is going to be 7-hydrogen sulfide, molar masses of all of these compounds. Now let's figure out, well, how many moles does each one of these samples contain? Okay, so we know we've got a mass of 114 grams. So, well, I've written these things upside down, so we're going to have to rearrange all of them to cancel out grams and get moles. But now that we've got all that taken care of, we can cancel out grams in each one of these with the units of moles. But this, actually, unit of moles is moles of pH3. So we have one mole of pH3, or moles of H2O. So we have one mole. We're looking for a number of hydrogen atoms. So we've got to figure out the number of moles of hydrogen atoms we have in each one of these. So then we know that for each mole of pH3, we have, since we've got three hydrogen atoms in each molecule, there's going to be three moles of hydrogen atoms. So we're just going to do that, where you factor down. One mole, you notice, we cancel there, and we're down to moles of hydrogen atoms. Let's do that for all of them. There's two moles of H atoms per one mole, two moles. So then all of these were down to moles of hydrogen atoms. But we're still not to what we're looking for, because it says the number of hydrogen atoms. A mole is a unit of counting, so we're going to have to take that mole and figure out how many units are in a mole. So remember for every one mole of hydrogen atoms you have, you have 6.022 times 10 to the 23rd hydrogen atoms. moles of hydrogen atoms cancel out, and that's going to give you your answer there. So we're just going to do that to every one of these. 23rd H atoms, 23rd H atoms, but H atoms cancels out, and all of these we're trying to figure out now what the answer is. So all we've got to do is take our calculator and multiply these across. So the first one is going to be 1, 1, 4, 0, 5, since we only have three. That's the number we would kind of expect there to be, or 114. So let's do it for the next one, 1, 1, 4 times 2 times 2. I'm running out of room here, but I think we have enough room to write which ones are right in order. Notice they're all times 10 to the 24th, so we could just look at the number here. This one, 7.62 is bigger than all the other ones, so that one's going to have the most number of hydrogen atoms. That's water. It's going to have the most. Then the next most would be 6.06 times 10 to the 24th. That's going to be pH 3. The next most is going to be 4.03 times 10 to the 24th, so that's H2S, and then last of course is going to be H2S. So the final answer that you would box in this one would be that. So hopefully that 12th minute...