1. Understanding Density

2. What is Density? The ratio of the mass of a substance to its volume D = –Volume – amount of space an object takes up –Mass – the amount of matter (stuff) in an object MVMV

3. What is Density? –Volume – amount of space an object takes up –Mass – the amount of matter (stuff) in an object –So density is the amount of stuff in a certain space…. –The more stuff in a space  the higher the density

4. Which box has more stuff in it? Which box has the greatest density? Why does this box have the greatest density? BECAUSE IT HAS MORE STUFF IN IT!!!

5. Think about it… What is the most dense “phase” of matter? –SOLID….why? Has the most “stuff” (matter) in the smallest space Huge Balloon versus Golf Ball. Which on is more dense? Golf Ball …. Why? Has the most “stuff” (matter) in the smallest space

6. Heating an object… Expands- volume increases = more space Matter – Stuff inside remains the same Therefore: same “stuff” (matter) in a bigger space = lower density

7. Temperature & VolumeTemperature & Density temperature volume density

8. Breaking up … If you break an object of uniform composition in half, what happens to its density? MASS =100 gVOLUME = 10 cm 3 DENSITY = 10 g/ cm 3

9. Breaking up … If you break an object of uniform composition in half, what happens to its density? MASS =50 g VOLUME = 5 cm 3 DENSITY = 10 g/ cm 3 WHY – MASS AND VOLUME CHANGE PROPORTIONALLY (EQUALLY)

10. Breaking up … If you break an object of uniform composition in half, what happens to its density? MASS =50 g VOLUME = 5 cm 3 MASS =25 g VOLUME = 2.5 cm 3 DENSITY = 10 g/ cm 3