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Convection Density of Fluids Investigation 5, Part 1 Slide 2 Setting the Scene Observe the bottles. What is happening? Can you explain why the liquids behave the way they do? Slide 3 Challenge of the day There are four liquids Layer all four liquids in a section of straw Slide 4 Materials Straw & holder Container with 4 liquids Pipettes (4 ) Paper Towels Slide 5 Push the angled edge of the straw over the ball of holder so it sits at a slight angle. Using the straw Slide 6 Gently squeeze a few drops of each liquid into the straw Using the straw Slide 7 Gently squeeze a few drops of each liquid into the straw Let the drops slide down the side of the straw Using the straw Slide 8 Gently squeeze a few drops of each liquid into the straw Let the drops slide down the side of the straw Using the straw Slide 9 Gently squeeze a few drops of each liquid into the straw Let the drops slide down the side of the straw Using the straw Slide 10 Page 21 in Lab Notebook Slide 11 Directions Record all trials using colored pencils on the Liquid Layers worksheet Circle the correct layering diagram Answer the question for Part 2 Slide 12 Discussion What do you think caused the salt solutions to layer this way? Slide 13 Discussion The liquids are made with water and salt How is it that some salt solutions can be heavy and some light if they are made with the same materials? Breakpoint Slide 14 Bottles Observe the bottles How are these 2 bottles like the straw challenge? How are they different? Slide 15 Ponder this! Which is heavier? Gold or Feathers Slide 16 Weight and volume Cup of beans and the cup of foam cubes Which do you think is heavier? Think about this: Cups are the same size and full How can one be heavier than the other? Slide 17 Mass vs Volume Mass The amount of stuff in an object You find mass by measuring the weight Volume Is how much space a sample of matter occupies Measured using graduated cylinders Slide 18 Density The amount of matter in a volume of material Density = mass / volume Ratio between the mass of matter and its volume Equal volumes of material One is heavier than the other Heavier material is denser Slide 19 Density Problem I have two samples of salt water. Sample 1 is 45 ml, and its mass is 54 g. Sample 2 is 120 ml and its mass is 132 g. Which sample is denser? Slide 20 Consider salt solution Do you think density played a role in the layering activity? Slide 21 Determining Density Will these 2 identical volumes of liquids have the same mass? Make a prediction! Slide 22 Masses of cups Mass 25.0 gMass 28.2 g Which solution is denser? How do you know? Slide 23 Discuss with group Which solution would layer on top of the other? What does this tell you about how liquids of different densities interact? (Which one will be on top?) Slide 24 Masses and Volumes On the Liquid Layers Write the masses and volumes MassVolume Red25.0 g25 ml Green26.5 g25 ml Yellow28.2 g25 ml Blue30.0 g25 ml Slide 25 Densities of colored salt solutions Turn to Calculating Density Transfer data fromLiquid Layers page Calculate the density (D = M / V) and answer the questions at the bottom Slide 26 Answer Red = g/ml Green = g/ml Yellow = g/ml Blue = g/ml Slide 27 Density of water is 1.0 g/ml Pine wood has a density of 0.60 g/cc. Will it float or sink in water? Styrene plastic has a density of 1.7 g/cc. Will it float or sink in the red saltwater? What general statement can you make about floating and sinking in water? Slide 28 Revisiting density bottles Observe the bottles again Explain those observations in terms of density Slide 29 Revisiting density bottles The red liquid is less dense than the clear liquid The clear liquid is less dense than the red liquid The red liquid is denser than the clear liquid The clear liquid is denser than the red liquid Slide 30 Review: Density Density is a physical property of matter. The density of any object can be calculated if you know its volume and its mass Volume can be measured in milliliters (ml) or cubic centimeters (cc). The unit most often used is cubic centimeters, but milliliters can be used with fluids. 1ml=1cc Mass can be determined by weighing. Density is mass per unit volume. Always include the units with your calculations and answers. Slide 31 Response Sheet Turn to page 25 in your lab book. Answer the question and turn your worksheet in. Slide 32 Reading Read Density on page 27 of the Green Resource Book Answer questions for homework Slide 33 Density Practice Complete : -Density Identities -What is Density? -How is Density Measured?