 Okay, let's do a similar problem to the last one, but this time we'll be calculating the density of a liquid, so that's going to be more dense, remember, than the gas that we did the last problem, but probably less dense than the solid that we did the first problem. But anyways, we're calculating the volume again. So remember, a density problem, density, mass, and volume, so it says calculate the volume in milliliters, so that's important, of a liquid that has the density of 1.20 grams per mill. Liquids and gases are usually in units of milliliters and liters respectively. And a mass of 5.00 grams, 5.00 grams, so we don't know the volume. And again, if you wanted to remember the density formula, you could, they need to because you've got grams and grams and milliliters, and you can figure out which one cancels, so, or how to cancel them, hopefully, right now, 1.20. This here, this density, this is just a conversion factor for whatever liquid this is. This is saying that for every 1 milliliter of this liquid, it's 1.20 grams. So it's doing things this way, and in chemistry you'll find a lot of these things. So you can use this as a conversion factor. So remember, with the dozen endowments, we could have done the same thing, right? You divide something by itself. It's the same thing. So in other words, we could flip this over, okay? So why is that important? We want to have those on top. So if we just flip this over, just get our calculator out and say 5 divided by 1.2 equals 4.1666666. So this is the 3-6-6, so 4.1666666 is higher than 5, so we're going to say 4.17, and you got to remember your units, because your number doesn't mean anything without units. So they're saying, well, how many mills do you have of this stuff if you've got 5 grams of it? Well, you've got 4.17 mills. And does that make sense? You should have less than 5 mills. Why? Because 1 mill weighs more than 1 gram, if that makes sense. So again, we didn't even have to do, we didn't even have to memorize that density stuff, right? So if you want to do it, density equals mass over volume. You could rearrange this equation to get volume mass divided by density. And is that what we did? That's what we did. If we flip this thing over, it's like doing the inverse, so mass divided by density. OK? So try it on your own. It's interesting to see that they work out the same way. So hopefully there's no questions, because the camera's stuck.