5. Quick Review Oral Presenters: 5. If you have a unit label of hg/mL what kind of number do you have? Managers: 6. What type of number is 2.7 cc? Timer Designers: 7. A substance was dropped into a G.S. holding 300mL rose to 428 mL. What type of problem is this? Materials Managers: 8. What units identify DENSITY numbers?

6. Quick Review Oral Presenters: 9. A cube measures 7.9 cm on each side. What type of number is 7.9 cm ? Managers: 10. If you have two pieces of Zinc with the same volume will their masses be the same or different? Why? Timer Designers: 11. What units identify VOLUME numbers? Materials Managers: 12. If the volume is different for two pieces of Lithium will the mass be different? Why?

7. Quick Review Oral Presenters: 13. You have a number with cg unit and a number with g/cc units . What formula do you use to find the missing variable? Managers: 14. If you have two pieces of Zinc with the same volume will their DENSITY be the same or different? Why? Timer Designers: 15. You have MASS and DENSITY . What function? Materials Managers: 16. You have DENSITY and VOLUME . What function?

8. Quick Review Whole Group: 17. Two pieces of Gold have the same mass . Is their DENSITY the same or different? Why? 18. If you have two pieces of Sulfur with the different volumes will their DENSITY be the same or different? Why? 19. You have 27 kg/m3 and 52 kg. What formula do you use? 20. You have 38.6 liters and 52 grams per liters . What formula do you use?

9. Answer in complete sentences : 8. How is Density useful in identifying substances? Explain why a substance, such as gold, cut into different sizes, would have the same density.

11. The following formulas are for finding different variables in density problems. Density Formulas m m v D = = = D v x m D v

12. Sample Chemical Symbol Density g/cm3 Physical Attribute Aluminum Al 2.7 Not Heavy Copper Cu 8.9 Orange Methane CH 4 .668 Strong Odor Gold Au 19.3 Yellow Ice H 2 0 .917 Crystalline Iron Fe 7.8 Rusts Lead Pb 11.3 Very Heavy Seawater H 2 0 + 1.4 Heterogeneous Wood (average value) Cellulose 0.8 Can Float