1. 7.2 Fluids and Density 1)A fluid is any form of matter that can flow. a)Liquids and gases are fluids since they do not have a fixed shape. b)Solids are not fluids. See page 260 Solid, Liquid, and Gas Density 1)Density is the amount of mass for each unit of volume. Density describes how closely packed together the particles are in a material. 2)Fluids that do not mix, layer themselves according to their density. 3)Less dense fluids “float” on top of more dense fluids. See pages 262 - 263

2. Measuring Density See page 264 1)Both mass and volume are required when calculating density. 2)Mass:  Mass can be measured using a scale or balance. 3)Volume:  For objects that are block shaped, volume can be calculated by measuring the block and then using the equation: volume = length x width x height.  For objects with irregular shape displacement is the method used to find the volume.

3. Calculating Density See page 265 Calculate density using the following formula Answer the following: 1.What is the density of a 4 cm 3 rock that has a mass of 24 g? 2.A 5 ml sample of motor oil has a mass of 4.5 g. What is the density of the motor oil? See next slide for the answers.

4. Calculating Density See page 265 Density can be calculated using the following formula: Answer the following: 1.What is the density of a 4 cm 3 rock that has a mass of 24 g? 2.A 5 ml sample of motor oil has a mass of 4.5 g. What is the density of the motor oil? Answers 6 g/cm 3 0.9 g/mL