1. DENSITY RULES

2. All pieces of the SAME material (no matter what the size) should have the density. When a piece breaks, the density of each piece is the same as the original. SAME size density Constant relationship Why? The atoms are still packed the same

3. How to change the density of a material?

4. The only way to change the density of a material is to change the way the atoms “pack”. The easiest way to do this is to change its temperature or pressure.

5. a. Temperature

6. As an object is heated, it expands (volume increases) and the atoms become less packed. Therefore the object becomes less dense.

7. When an object is cooled, it contracts (come together) and the atoms become more packed. Therefore, the object becomes more dense.

8. Decreases Density Indirect Relationship As temperature increases, density __________ Temperature

9. a. Pressure Pressure – the force applied to a unit area of surface Volume – decreases Mass – remains the same Density - increases

10. D pressure Direct Relationship As pressure increases, density ____________ Increases

11. 3. Density of Water Density of water is: 1g/cm 3 It is most dense at 4 o C because the water expands above and below this temperature ESRT Page 1

13. 4. Less dense objects will on top of more dense objects. The dense objects will be on the bottom and the less dense on top. float

14. Graphing and Density If volume is on the independent variable (X-axis) and mass is the dependent variable (Y-axis), then the slope of the line will indicate the ________ of the material being graphed. density

15. Volume (cm 3 ) Mass (g) Slope = rise run = mass volume = Density Slope = density

16. Volume (cm 3 ) Mass (g) Slope = rise run = mass volume = Density = 3 = 1g/cm 3 Density of Water

17. Volume (cm 3 ) Mass (g) run volume Water Less Dense More Dense