Sweet Density & Plate Tectonics
•Explain the Theory of Plate Tectonics
•Explain crust movement by using a visual model
•Make and test a hypothesis
•Collect, organize and use data from a measurement
tool
Density
Less Dense, More Dense…HUH?
Let’s Figure Out Density for a
Twix and a 3 Musketeers!
Candy Bar Density
• Density = mass / volume
• Mass it in grams with a triple beam
balance
• My Best Friend (Middle, Back, Front)
Triple Beam Balance – Mass (g)
Graduated Cylinder – Volume (mL)
Cylinder with Candy
- Cylinder Only
Volume of a Solid
30 mL
- 23 mL
7 mL
Using the Data
• Twix
Mass - ____g ÷ Volume – 15 mL = _____g/mL
• 3 Musketeers
Mass - ____g ÷ Volume – 20 mL = _____g/mL
Calculating Density
Predict
• If the density of water is 1 g/mL
• Will our candy bars sink or float?
Making Predictions
Twix vs. 3 Musketeers
Modeling the Continental and
Oceanic Crusts
Twix = thinner, more dense
3 Musketeers = thicker, less dense
If I collide a Twix with a 3 Musketeers
then_______________________,
because_______________________.
Twix vs. 3 Musketeers
• Draw a picture of what happened
• Label the candy bars using these terms
– Convergent Boundary
– Less Dense
– More Dense
– Subduction
– Oceanic Crust
– Continental Crust
– Add arrows of directional movement
Creating a Graphic Model
Videos 
• Divergent Boundary
• Convergent Boundary
• Transform Boundary
• Types of Faults
• Plate Movement Direction: (picture)
Density of the Earth’s Crusts
• Oceanic Crust = 3 g/mL
• 4-7 miles thick
• Made mostly of Basalt (an igneous rock)
• Continental Crust = 2.7 g/mL
• 20-25 miles thick on average (max – 45 miles thick!)
• Made mostly of Granite (an igneous rock)
Update your Pictures
• Check Labeled Terms
– Convergent Boundary
– Less Dense
– More Dense
– Subduction
– Oceanic Crust
– Continental Crust
• Add numbers of Densities
• Hang Picture & Report out to class 