Reference: Bartholomew and the Oobleck by Dr. Suess
Thanks to Don Tincher, Berlin Middle School, who showed us how much fun oobleck is to make and test.
CONCEPTS: We think of solids as being hard and liquids being runny. Because of he peculiar properties of cornstarch mixed with enough water to give it some short-range structure (but not long-range structural integrity like a standard solid), especially under pressure, oobleck, the name given to this mixture after the Dr. Suess book, exhibits both hardness and runniness. With oobleck, however, it is less important to understand exactly why it behaves as it does but to experiment with it and observe it and handle it. It is especially valuable to THINK about what it teaches us about solids and liquids and IMAGINE what would happen if it did fall from the sky as in the story.
SAFETY: Although cornstarch is edible, oobleck should NOT be tasted, especially if children mix it by hand. The floor will be slippery if oobleck or water is spilled. Goggles should probably be worn until the oobleck stage is achieved to prevent powdered cornstarch from getting into anyone's eyes.
ACTIVITIES:
Note: Oobleck is messy, so you may want to arrange to have our session in a science lab or other such location if your classroom is carpeted. Warn your custodian that you might have a little messier than usual classroom. Proper oobleck should be green in color (as in the book), but to avoid staining hands, clothes, etc. we'll make "albino oobleck" instead.
Oobleck should be mixed by adding water very slowly until it reaches the proper dry-but-runny consistency. Then each child should have a chance to handle and study the oobleck. We'll make zip-loc bags available to take home some.
Wisconsin Standards:
Science Inquiry: C.4.2, C.4.7
Physical Science: D.4.1, D.4.2, D.4.3
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