PURPOSE: Demonstrates how density stratification (differentiation) in interior of planet (e. g., earth) arises.
DESCRIPTION: Heavy balls represent dense material (e. g., iron or nickel). Light balls represent light material (e. g., silicates). Use wooden plank to vigorously mix the balls, then remove the plank and watch heavy balls settle. Mixing simul ates the hot molton interior of a young planet. Settling simulates differentiation in molton interior.
SUGGESTIONS: Make it splash; students like it when the instructor gets wet.
REFERENCES: (PIRA 8A20.21)
EQUIPMENT: Plastic tank with water, superballs, light balls and plank.
SETUP TIME: 5 min.
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