Student Exploration: Density Experiment: Slice and Dice
Vocabulary: density, mass, matter, volume
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
What do you think would happen if you threw a block of polystyrene (Styrofoam™) into the water?
What would happen if you broke the Styrofoam up into lots of pieces, then threw the pieces into water?.
What would happen if you threw a big rock into water?.
What would happen if you broke the rock into little pieces, then threw the pieces into water?.
The Density Experiment: Slice and Dice Gizmo™ allows you to compare different-sized pieces of the same material.
Check that Polystyrene is selected. Drag the whole polystyrene piece into the water.
Does it sink or float?
Click Reset, and then click Slice to cut the polystyrene into pieces. Drag each piece into the water and then back to the block.
How do you think the amount of a material affects its tendency to sink or float?
Slice and dice
Get the Gizmo ready:
Click Reset. Check that Polystyrene is selected.
A calculator is recommended for this activity.
Introduction: The density of a material is the amount of mass per unit of volume. Density is calculated by dividing an object’s mass by its volume.
Question: How does density depend on the amount of material?
Form hypothesis: How do you think cutting up a material will affect its density?
Collect data: Click Slice. Choose a piece of polystyrene and drag it onto the Material investigation tray. Record the mass and volume, then calculate the density by dividing the mass by the volume. Replace the piece, and then repeat for the remaining pieces.
Analyze: What do you notice about the density of the polystyrene pieces?
Predict: What do you think is the density of the whole block of polystyrene? .
Test: Click Reset. Drag the whole (uncut) block of polystyrene onto the Material investigation tray. Record its mass and volume and calculate the density.
Mass: Volume: Density:
Apply: An archaeologist finds a golden figurine. How could she determine if the figurine is solid gold without cutting it?
Sink or float?
Get the Gizmo ready:
Question: The density of water is 1.0 g/mL, which is equivalent to 1 g/cm3. How does an object’s density affect whether it sinks or floats in water?
Form hypothesis: How do you think an object’s density relates to whether it sinks or floats?
Collect data: Measure the mass and volume of each known material, and calculate its density. Then drag each material into the water to see whether it sinks or floats.
Analyze: How does an object’s density determine if it will sink or float?
Apply: Find the density of Unknown A and Unknown B. Based on their densities, predict whether each will sink or float. Then, test your prediction using the Gizmo.
Extend your thinking: Compare the three floating materials. How does the density of each material relate to how high it floats in the water
What two things did you learn about matter from completing this Gizmo lab? (Please use complete sentences.)
Consider the picture from the gizmo below. Based on what you have learned from the Gizmo, make a claim about the relative densities about the two liquids. Use evidence from the picture to support your claim.