Dancing Raisins

What You Need:

• Clear Drinking Glass
• Clear Carbonated Drink (7-up seems to have the best results)
• 10-15 raisins

Ask Yourself:

• What do you think will happen to the raisins when you put them in the 7-up?

Directions:

• Fill the glass with the clear soda
• Drop the raisins into the glass and watch
• (If you want to continue the experiment, you can try other items in your kitchen to see which ones work best.  Try things like macaroni noodles, lentils, corn, or dried cranberries and see what happens!)

The Big Science Words:

• Now you've discovered that the raisins in the glass will begin to "dance" by bobbing up and down with the bubbles in the soda.  This happens because of a few big science words: nucleation, density, volume, and mass.
• Nucleation: this is when the air bubbles from the soda collect in all the little pockets and wrinkles in the raisin.
• Density, Volume, and Mass: those little air bubbles are giving those raisins their own little "floaties."  When the air bubbles attach to the raisin, they increase its volume, or make it bigger.  But, because they're just bubbles, they don't increase its mass; they don't make it any heavier.  So when the raisin is covered with bubbles it becomes less dense than the soda around it and it floats.  When the bubbles pop at the surface, it becomes more dense than the soda again, and down it goes!