1. Don’t let DENSITY weigh you down…it’s easy!!

2. What is Density? The relationship between Mass and Volume. The relationship between Mass and Volume. Density is a property of Matter. It will always be the same quantity for a piece of matter regardless of shape or size. Density is a property of Matter. It will always be the same quantity for a piece of matter regardless of shape or size. Describes how tightly packed together atoms are in different materials. Describes how tightly packed together atoms are in different materials.

3. So, what is density? Something with a large density has a lot of mass contained in a unit volume Something with a large density has a lot of mass contained in a unit volume Something with a small density has less mass contained in a unit volume Something with a small density has less mass contained in a unit volume For example, THIS CLASS. For example, THIS CLASS. What about two identical suitcases? What about two identical suitcases?

4. Consider the diagram above. Which circle, A and B, is more dense? Consider the diagram above. Which circle, A and B, is more dense? –If you said A, YOU’RE CORRECT! Since A has more particles (mass) in the same volume as B, A would be more dense. Since A has more particles (mass) in the same volume as B, A would be more dense.

5. Equation Density is the ratio of mass to volume. Density is the ratio of mass to volume. D = m D = m vExample: What is the Density What is the Density of a bolt that has a mass of 14g and a volume of 2ml? D= m / v D= m / v D= 14g / 2ml D= 14g / 2ml D= 7 g/cm 3 D= 7 g/cm 3 Don’t forget units! Units for density is g/cm 3 Don’t forget units! Units for density is g/cm 3 V D M

6. Properties of Density Heavy vs. Light Heavy vs. Light –Many times when we talk about things being heavy or light what we are really talking about density. –The reason things are “heavy” is because it has a high density and has a greater mass than expected for its volume. Sink vs. Float Sink vs. Float –Matter that floats has a lighter density than the substance it is in –Matter that sinks has a greater density than the substance it is in

7. Predictions: If you think of two cans of pop, Coke vs. Diet Coke, which one has a greater density? If you think of two cans of pop, Coke vs. Diet Coke, which one has a greater density? –Which one had a greater density, Coke, Diet Coke or water? –Why? The density of water is 1 g/cm3 The density of water is 1 g/cm3 If you think of hot and cold water, which has a greater density, hot water or cold water? If you think of hot and cold water, which has a greater density, hot water or cold water? –Why? If you think of Carbon Dioxide gas, which has a greater density, Carbon Dioxide or the “regular” air? If you think of Carbon Dioxide gas, which has a greater density, Carbon Dioxide or the “regular” air?