Rainy Days

When rainy days keep students inside for recess, use the extra time for science! Keep easy-to-do science activities and experiments together with any necessary materials in resealable plastic bags. Then hand them out and have students work with partners to complete the activities. It's a great way to squeeze in a little more science time, plus your students will look forward to indoor recesses.

Chemical Reaction Experiment - Bobbing Raisins

Steps

1.  Pour the carbonated drink into the glass/jar. 2.  Drop the raisins into the glass/jar. What to see what happens to the raisins!!! The bobbing up and down works because the bubbles of carbon dioxide gas in the drink are much less dense than the drink or the raisins. Once the raisins start bobbing up and down, they will continue to rise and fall for about an hour. - Raisins are denser than the carbonated drink, so they will sink. - Gas bubbles attach to the wrinkles on the raisins. - When the raisins are covered with the bubbles they become less dense than the drink, so they start to rise. - The gas bubbles start bursting and then the raisins become denser than the drink, so they sink again.

http://www.lovemyscience.com/bobbingraisins.html