 These are my hard hitters, and I'm going to keep working these until I actually get them, and that's just how I feel about it. Well, all these recordings are there for you, you know what I'm saying? So we're going to put them up, and then you're going to watch them until you get them. And the thing is, you can already see that you're getting them yourself, you know what I'm saying? You saw, it's just that one step that you needed, that cut in half, you know? So it's just you're missing a step every place, you know? Yeah, that's what I noticed. Most Jin Kim people's probably. What I see is kind of thinking out of the box a little bit, on a lot of the questions, and I can't seem to grasp that. Yeah, sure. It's out of the box doing a lot of this. Yeah, but a lot of it is like, you want to think, and I know it's, I don't want to sound like too, whatever, but a lot of it is like, really, if you think about it, it's like common sense, you know what I'm saying? You always want to think, I've learned this somewhere else, not just in chemistry class, I've learned this, doing this type of thing, like boiling water, or something like when I was cooking or something, you know? You always want to go back to that type of stuff, you know? Well, that, and you think about density or something, you know inherently about density, which is the problem we're about to do. When you throw a rock into the water, and it sinks, you know that the rock is more dense, you know? But that inherently, you know, so if you're putting like, if there's a question that says, there's this rock, you know, and it sinks to the bottom of water, you know, and you're trying to figure out what the density of it is, and you put like something like 0.7 something, then you know you've done something wrong, but a lot of people won't catch that because they're like, because the density of water is 1, you know what I'm saying? Yeah. So it must be heavier, the density must be more than 1, you know what I'm saying? So, I don't know. So you want to always catch yourself with common sense because you know the rock fell, went to the bottom of the water, so it must be more dense than water, you know? Yeah. So, think about that, you know? I've got a question. Okay. Whenever I'm doing a mole problem... Let's do this one first. Let's do this one first, okay? Yeah. We'll talk about that when we're doing a mole problem. Yeah. Okay. So, a sample of blood was found to have a density of 1.5 grams per mil, okay? So, density, that's the first thing we want to do. One point... Sorry, 1.05 grams per mil. Now remember, this is like the text messaging way of writing it. We want to... For chemistry, we want to write it out normal, okay? Yeah, first. So... Right. 1.05 grams per one mil, okay? What would be the mass of this material? So, this is grams of blood per mil of blood. What would be the mass of 1.000 liters of this material? So, it's asking you, what is the mass of 1.000 liters? So, what do you got here? You know some things already, right? You know the... We got our density. You know the formula for density, right? Density equals... Mass of a volume. Mass divided by volume. Yes. You've got the volume. You've got the mass. Are you looking for the mass and you've got the density, right? So... So, if you want to do it that way you can, I prefer to just do it cancelling units out, you know? Okay. And this is again... This is what we were doing the other day if you recall when I was like... Oh yeah. Desmond. Okay, so let's do it the other way because I think it's much easier, you know? Okay, so what units do we have here? Leaders, right? Leaders, yes. And we have units of milliliters here, okay? So let's just convert this milliliters to what a leader would be, okay? Okay. So, you know the conversion factor, right? How many mills are in a leader? 1,000, right? Yes. 1,000 mills in one leader. That's the conversion factor. So divide or cancel, cancel. And then what do we do now? We say 1.05 grams times 1,000, right? Mm-hmm. Which is going to be 10, 50 grams. Okay. So that's all right. So remember what did we say, right? This is 1,050 grams of what? Blood. Blood, right? Mm-hmm. Her what? Leader of what? One leader of blood. Of blood. What did the question ask you? It said... What is the mass? What is the mass of one leader of this material? It's 1,000. We've already figured it out. It's the answer, yeah. It's all that. If you try to do it like that, you know, you're going to try to confuse yourself, you know? Oh, man. Just cancel the units out, man. It makes it a lot easier. But anyways, think about it this way. We really haven't finished this problem, okay? Because it's asking you, well, what's the mass of this particular volume of blood? Because if this was a different number than 1.000, say it was 3.2 or something like that, we wouldn't be finished with this problem yet, okay? But because it's 1.0, we kind of are. But we're still going to go the extra mile just to show the cancellation of that, okay? So remember, this volume is 1.000 liters of blood, right? Yes. So let's figure out the mass then. So the mass, well, we know 10, 50 grams of blood per 1 liter of blood. And we're going to multiply that by 1.000 liters of blood. That'll cancel out our liters and that'll give us that mass. And again, we did that in the step before. But if this volume was different than 1, we would have had to do this next step. So it's good to show. And what does it say? It says to express your answer with a proper number of sig figs as you always should. This has three sig figs. This also has three sig figs actually, okay? Because that last zero is not significant because it doesn't have a decimal there. You could also express it another way. 1, 0, 5, 10 to the 1, 2, 3. Or you could express it another way, right? You could say, if you didn't like this scientific notation, I know this is a multiple choice test. So there's only a certain answer. But let's just keep going for the, just for the hell of it, you know? So what do you know? You know that 1 kilogram equals 1,000 grams? Cancel, cancel like that, right? So take that, divide it by 1,000. What do you get? 5 kilograms, which also is three sig figs. So you could have stopped here, right? Because of course this is three sig figs. You could have stopped here. That's three sig figs, okay? If you were wanting to have a wild hair or you were like, you didn't really know your sig fig rules and you decided, man, I really don't know. I'm going to just put that decimal point there, you know? That indicates to us that that zero is significant, okay? That would be wrong, right? And that's wrong, yeah. So you got to not do that, okay? So you did that wrong. We cool with that problem? Yeah. Okay, good.