| Learn about: chemistry, bubble, and isopropyl alcohol |
A sphere is a very special shape in nature. Liquids form into spheres due to internal forces. Investigate density and shape. Materials: Small jar with sealable lid; tap water; isopropyl rubbing alcohol; vegetable oil; teaspoon Procedure: 1. In a mixing bowl, mix three parts alcohol to one part water (example, 3 half cups of alcohol to 1 half cup of water). Stir to mix. 2. Pour into jar. 3. Measure 1 teaspoon of vegetable oil and carefully bring the spoon close to the surface of the alcohol-water mixture in the jar, then gently tip the spoon over. If you’ve done the job right, a single blob of oil will slide into the jar. What happens to the oil? 4. If the blob of oil is floating on the surface, carefully add a bit more alcohol to the mixture using the teaspoon; if the blob sinks to the bottom of the jar, spoon in some more water. What happens? Can you get the blob of oil to form a bubble that hovers in the middle of the jar? Is the bubble round? Try cutting the ball of oil with a butter knife. What happens? When you’re finished experimenting, secure the lid on the jar — you now have an object of scientific curiosity. Now, explore! Can you get the blob of oil to form a bubble that hovers in the middle of the jar? Is the bubble round? Try cutting the ball of oil with a butter knife. What happens? When you’re finished experimenting, secure the lid on the jar — you now have an object of scientific curiosity.
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