TOPIC : Lab Skills AIM : How do we determine density?

1. DO NOW: Explain how layers exist in cappuccino. Layers exist in cappuccino because ________________________________________________________________________________ TOPIC: Lab SkillsAIM: How do we determine density?

2. Density The measure of the amount of mass that is in each unit of volume mass per unit volume

3. Instruments needed To measure density Triple beam balance for mass Graduated cylinder for volume of a liquid Metric ruler for volume of a solid

4. Units used for density or Grams/ml or Grams/cm3

5. A B Box A has a greater density than Box B Because Box A has a greater mass (more matter/ molecules) in the same volume

7. Warm air rises b/c it is less dense than cold air which sinks.

8. 1 gm/mL Density of water

9. Why will an object float or sink? FLOATS when the density of the object is LESS than the density of the liquid.

10. Less dense than water SINKS when the density of the object is GREATER than the density of the liquid. More dense than water

11. Which is more dense? Salt water

14. Warm water rises b/c it is less dense than cold water which sinks.

15. Density Facts Each pure substance has it’s “own density” no matter what size it is.

16. So……If I Cut the substance in half each half would still have the same density cut it in half

17. M = 20 gm V = 10 mL Density= 20/10 = 2 gm/mL Cut the block in half M = 10 gm V = 5 mL Density= 10/5 = 2gm/mL

19. wood plastic rubber copper

20. AIM: Mass How is denisty calculated? Density = Volume M D V

21. Denisty = Mass / Volume M Mass = Density X Volume D V Volume = Mass / Density

22. 1. What is the density of a metal block that has a mass of 525 gm and a volume of 50 cm3? Example #1:

23. D = m v D = 525 gm 50 cm3 D = 10.5 gm/cm3

24. What is the block made of? Silver = 10. 5 g/cm3

25. The mass of a marble is 8.8 gm. It has a volume of 2 mL. What is it’s density? Example #2

26. D = m v D = 8.8 gm 2 mL D = 4.4 gm/mL

28. Example #1 M = 45gm D = 20.1 gm/mL Volume = ? M D V

29. V = M D V = 45 gm 20.1 gm/mL V = 2.2 mL

30. Will this object float or sink in water? Why? Sink It’s density is greater than the density of water (1 gm/mL)

31. Example #2 D = 3.5 gm/mL V = 1.6 mL Mass = ? M D V

32. M = D x V M = 3.5 gm/mL x 1.6mL M = 5.6 gm