1. WALT: Gain background knowledge on density to lay the foundation for future learning Define density various ways Compare the densities of 2 objects 1

2. Density: Warm Up Questions What is the meaning of “population density”? Which state do you think has the greatest population density? Which state do you think has the lowest population density? 2

3. Population Density: the number of people living in a particular area (people per square mile) 3

4. Greatest Population Density: New Jersey! Yay! Estimate the following on your sheet: # of people: Area: Population Density: 8,707,739 8,721 mi 2 ~998 people/mi 2 4

5. Lowest Population Density: Wyoming! Estimate the following on your sheet: # of people: Area: Population Density: 530,000 97,818mi 2 5.4 people/mi 2 5

6. 6

7. Mass: Amount of matter in a substance; measured in grams (g) with an electronic balance 7

8. Volume: Measure of the amount of space Solid units: cm 3 Liquid/Gas units: mL Irregular Objects - Water Displacement method Regular Objects - Measure and calculate 8

9. 1 cm 3 = 1 mL 9

10. Density: Definitions There are 6 definitions of density. Each of these definitions is explained on the next 6 slides, and there is a spot for you to copy each definition on your Powerpoint guide. 10

11. Density Definition #1 Density = mass volume 11

12. Density Definition #2 Density = unit of mass unit of volume 12

13. Density Definition #3 Density = known mass known volume 13

14. Density Definition #4 Compactness: objects that are more dense are more compact Both cubes have the same volume This cube has more matter in it Therefore, this cube is more dense (or more compact) 14

15. Density Definition #5 Density = mass volume = g cm3 15

16. Definition #6: mass of 1 cm 3 of a substance 1 cm3 16

17. Comparing Densities #1 1 cm 3 of concrete vs. 1 cm 3 of air? 1a. Which has more mass? 1b. Which has a greater volume? 1c. Which has a greater density? Explain your reasoning for your answers. Concrete They have the same volume Concrete 17

18. Some known densities. In one cubic centimeter of gold there is 19.3 grams of matter. In one cubic centimeter of lead there is 11.4 grams of matter. In one milliliter of air there is 0.001 grams of matter. 18

19. 2a. Which has a greater mass? 2b. Which has a greater volume? 2c. Which has a greater density? Pb Wood Shavings Lead Block Lead block Wood Shavings Lead block Comparing Densities #2 19

20. Assume each box has a volume 1 cm 3 Assume each red ball is equal to 1 g of matter Calculate the density of each object—show your calculations: Substance A Substance B Comparing Densities #3 20

21. One of the substances with the highest density? Gold = 19.3g/cm 3 21

22. Most dense known substance Osmium—22.57g/cm 3 Hydrogen – 0.000089g/mL Least dense known substance 22

23. Floating and Sinking Density of Air = 0.0013 g/cm 3 Density of Helium = 0.00018 g/cm 3 Density of Tank = ??? 23

24. Density of Pure Water: 1.0 g/cm 3 Density of a person: less than that 24

25. Density Output On page 42 of your interactive notebook, draw a picture that represents an object of high density AND an object of low density. Represent the matter in each object with dots. Remember to label each object. 25