1. Density An Intensive Property

2. What are Extensive and Intensive Properties? “Property” refers to the characteristics of a material “Property” refers to the characteristics of a material Properties are divided into two sub-types – extensive and intensive Properties are divided into two sub-types – extensive and intensive Extensive properties are based on how much of the material you have Extensive properties are based on how much of the material you have Intensive properties are not based on how much of the material you have Intensive properties are not based on how much of the material you have

3. What are Extensive and Intensive Properties? Some examples of extensive properties are: Some examples of extensive properties are: Mass Mass Length, Width, Depth Length, Width, Depth Area and Volume Area and Volume Shape Shape Temperature Temperature

4. What are Extensive and Intensive Properties? Some examples of intensive properties are: Some examples of intensive properties are: Color Color Density Density Boiling/Freezing point Boiling/Freezing point

5. What are Extensive and Intensive Properties? Intensive properties are especially important to geoscientists since they can be used to help identify a material Intensive properties are especially important to geoscientists since they can be used to help identify a material One of the most commonly used is density One of the most commonly used is density

6. Mass, Volume, and Density Mass is the amount of matter contained in an object Mass is the amount of matter contained in an object Volume is the space that an object takes up Volume is the space that an object takes up Both mass and volume are extensive properties Both mass and volume are extensive properties Density (intensive) is the ratio of mass and volume Density (intensive) is the ratio of mass and volume

7. What is density? Density is a comparison of how much matter there is in a certain amount of space. Density is a comparison of how much matter there is in a certain amount of space.

8. Which one is more dense? Which square is more dense? Which square is more dense? WHY? WHY?

9. WHY? Now which one is more dense?

10. What is the formula for density? Density = mass Density = mass volume volume Units for density: g Units for density: g cm 3 cm 3 Units can also be written as g/ cm 3 Units can also be written as g/ cm 3 Correct answers ALWAYS CONTAIN UNITS!

11. Density Materials with a high density contain a large mass in a small volume Materials with a high density contain a large mass in a small volume Materials with a low density contain a small mass in a large volume Materials with a low density contain a small mass in a large volume Aluminum has a density of 3.7 g/cm 3 and iron has a density of 7.8 g/cm 3 Aluminum has a density of 3.7 g/cm 3 and iron has a density of 7.8 g/cm 3 If you have equal volumes of aluminum and iron – which will have the greater mass? If you have equal volumes of aluminum and iron – which will have the greater mass? If you have equal masses, which will have the greater volume? If you have equal masses, which will have the greater volume?

12. Density Density determines whether or not a substance will float in/on another substance. Density determines whether or not a substance will float in/on another substance. Objects will higher densities will sink, but objects with low densities will float Objects will higher densities will sink, but objects with low densities will float For example – cork (0.24 g/cm 3) floats in water (1 g/cm 3 ) but calcite (2.7 g/cm 3) sinks For example – cork (0.24 g/cm 3) floats in water (1 g/cm 3 ) but calcite (2.7 g/cm 3) sinks

13. Density Solids tend to have densities greater than 1 g/cm 3 (but they can be slightly lower) Solids tend to have densities greater than 1 g/cm 3 (but they can be slightly lower) Liquids tend to have lower densities than solids (there are exceptions) Liquids tend to have lower densities than solids (there are exceptions) Gases have very low densities (small decimals) Gases have very low densities (small decimals)

14. Let’s try a density problem together Frank has a paper clip. It has a mass of 9g and a volume of 3cm 3. What is its density? Frank has a paper clip. It has a mass of 9g and a volume of 3cm 3. What is its density? 1. Write down the given information: M = 9 g V = 3 cm 3 M = 9 g V = 3 cm 3 2. Write down the equation – fill in for variables D = M = 9 g = V 3 cm 3 V 3 cm 3 3. Circle answer…INCLUDE CORRECT UNITS 3 g/cm 3

15. Frank also has an eraser. It has a mass of 3g, and a volume of 1cm 3. What is its density? Frank also has an eraser. It has a mass of 3g, and a volume of 1cm 3. What is its density? 1. Write down the given information: M = 3 g V = 1 cm 3 M = 3 g V = 1 cm 3 2. Write down the equation – fill in for variables D = M = 3 g = V 1 cm 3 V 1 cm 3 3. Circle answer…INCLUDE CORRECT UNITS D = 3 g/cm 3

16. Work on these problems with your neighbor. Tad Pohl has a rock. The rock has a density of 2 g/cm 3. If it’s mass is 6g, what volume will Tad’s rock take up? Tad Pohl has a rock. The rock has a density of 2 g/cm 3. If it’s mass is 6g, what volume will Tad’s rock take up? R.M Pitt has a gel pen. The gel pen has a mass of 8g and a volume of 2cm 3. What is the density of the gel pen? R.M Pitt has a gel pen. The gel pen has a mass of 8g and a volume of 2cm 3. What is the density of the gel pen? 2 Minutes - - Ready, Set, GO! 2 Minutes - - Ready, Set, GO!

17. Now, try these on your own… Crystal Ball has a watch. It has a mass of 4g and a volume of 2cm 3. What is the density of her watch? Crystal Ball has a watch. It has a mass of 4g and a volume of 2cm 3. What is the density of her watch? Dan Druff has a wallet. It has a density of 3 g/cm 3. If it has a volume of 5 cm 3, what is the mass of Dan’s wallet? Dan Druff has a wallet. It has a density of 3 g/cm 3. If it has a volume of 5 cm 3, what is the mass of Dan’s wallet? 2 minutes…ready, set, GO!

18. Liquid Layers If you pour together liquids that don’t mix and have different densities, they will form liquid layers. If you pour together liquids that don’t mix and have different densities, they will form liquid layers. The liquid with the highest density will be on the bottom. The liquid with the highest density will be on the bottom. The liquid with the lowest density will be on the top. The liquid with the lowest density will be on the top.

19. Liquid Layers Check out this picture. Which colored layer has the highest density? Check out this picture. Which colored layer has the highest density?Green Which colored layer has the lowest density? Which colored layer has the lowest density?Yellow

20. Liquid Layers – Try on your own! Imagine that the liquids on the right have the following densities: Imagine that the liquids on the right have the following densities: 15g/cm 3 10g/cm 3 15g/cm 3 10g/cm 3 3g/cm 3 9g/cm 3 3g/cm 3 9g/cm 3 7g/cm 3 12g/cm 3 7g/cm 3 12g/cm 3 Match the colors to the correct densities. Match the colors to the correct densities. 3g/cm 3 7g/cm 3 9g/cm 3 10g/cm 3 12g/cm 3 15g/cm 3