Thursday, January 26, 2012

Dancing Raisins Science Experiment!

I drink a lot of seltzer water and Grace and Jack have been asking many questions recently about all of the bubbles in my water. We discussed how the bubbles are made from dissolving a gas called carbon dioxide. I thought it would be fun to conduct the classic dancing raisin experiment to demonstrate just what all of those carbon dioxide bubbles can do!

We hurried home right after Grace' ballet class this morning to do our dancing raisin experiment. Since I have been talking about making raisins dance with my seltzer water with Grace, Jack and Eve for the past few days, they were quite excited and very ready to finally conduct this experiment!

To conduct our experiment Grace and Jack placed several raisins at the bottom of their glasses. Eve excitedly watched with me nearby. I think Eve definitely sensed all of the excitement in the room with all of her squealing and clapping! Grace and Jack poured seltzer water into their glasses and were amazed to see their raisins start dancing!

Grace, Jack and Eve learned the science behind this experiment: Raisins sink in water because they are more dense. Since seltzer water contains dissolved carbon dioxide gas, those
bubbles attach themselves on the irregular surfaces of the raisins and make it float. When the bubbles pop, the dense raisins sink to the bottom again. This up and down motion caused by the bubbles make the raisin appear to be dancing!

Later this afternoon we tried the experiment again but with a few changes. This time we created our own carbon dioxide bubbles of gas by combining vinegar (acetic acid) with baking soda. The raisins REALLY danced when we created our own bubbles. We also tried the experiment using blueberries and discussed why our experiment worked with raisins but not with the blueberries -- it is because raisins are wrinkly and the carbon dioxide bubbles have places to attach to.

This was a great afternoon for us. Stay tuned tomorrow for pictures of Jack and Eve doing more science related experiments and activities!

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