In this video, I’ll walk through an example using density, and then I’ll talk a little bit more about some of the measurements we use in chemistry. Liquid mercury has a density of thirteen point six grams per milliliter. What is the mass of three milliliters of mercury? Now, this is kind of a simple problem, but I want to use it to talk about density. Density is given by the mass of an object or a substance divided by its volume. The volume can be thought of as how much space something takes up. The mass, we don’t say the mass is how how much it weighs because weight is actually a force, but mass, mass is like a gram, as we have here “gram of mass.” That same mass gram would have a difference weight, say, on the moon because it has a different gravitational force. Okay, the volume then in this case is given in milliliters. So the “m capital L” is just an abbreviation for milliliters, and volume can be given in liters or cubic centimeters or cubic inches. In the metric system, we have this special milliliter or liter to give a volume, but also if you see this cubic anywhere, and some length cubed, that is a volume as well. Okay, now this density formula is given as d equals m over v. This is often how you see it. But we want to find m. This is what we’re trying to find is the mass. “What is the mass?” is the question, so let’s just multiply by the volume on each side. And I know you probably looked at this and said, “Hey, I know I need to multiply by the volume,” but I’m just breaking this down so that you can understand exactly where this is coming from. So that gets rid of the v in the in the denominator here, and what we have is d times v equals the mass, or the density times the volume. In our example, that’s thirteen point six grams per milliliter times three milliliters, and that’s going to equal the mass. So that comes to a mass equalling forty point eight grams Now, If you found this video useful, then consider liking it or sharing it with a friend.