1. Bell Ringer O Convert the following measurement: 130 g = _______________mg

2. Calculations 3. Density – the amount of MASS in a given VOLUME - Density= Mass ÷ Volume - D = M / V

3. Practice Problem O Ex. The mass of a piece of halite is 15 g and the volume is 6.9 cm 3. What is the density of the mineral?

4. Practice Problem O Ex. The mass of a rock is 32 grams and the volume is 7 cm 3. What is the density of the rock?

5. Practice Problem O The volume of a piece of wood is 15cm 3 and the mass of the sample is 10 grams. What is the density?

6. Practice Problem O A graduated cylinder had an original water level of 13mL. A piece of galena, with a mass of 38 grams, was dropped into the graduated cylinder. The water level rose to 18 mL. What is the density of the galena sample?

7. O When the molecules in an object are close together, the material is more dense. 1. Solid – most dense phase

8. 2. Liquid – less dense because molecules are farther apart.

9. 3. Gas – least dense – most space between molecules

10. Density O If an object is more dense than the surrounding liquid it will sink. O If it is less dense it will float. O Which substance is an exception to this rule ? Water Why? Ice (solid) is less dense than water, so it will float

11. O Ex. The diagram below shows a tank filled with water. Wooden blocks of different densities are placed in the tank. Answer the questions that follow. Which block is more dense than water? Why? Which block is less dense than water? Why? Which block could have the same density as water?

12. Most Important!! O The density of a substance under normal conditions doesn’t change even if the size (volume) is different. Ex. Two pieces of clay of different sizes have the same density. Ex. Two cups of water filled to different levels have the same density.