Yep, you read right - I said Thanksgiving.  This was one to-do that just didn't make the cut during the busy holiday season.  But, we had all the materials (and time) the other day and it really doesn't have to be a Thanksgiving experiment....

Remember the Science Projects for Holidays Throughout the Year book?  This is another fun math and science activity found in it. 

To sum up the experiment, we compared unpopped kernels to popped kernels in volume and characteristics.  We made hypotheses as to what makes popcorn pop.  Then it was time for a demonstration.  We poured about a 1/2 cup of water in a glass bottle and placed a deflated balloon over the bottle top.  The bottle was carefully placed in a pot of slightly boiling water.  As the water in the bottle began to boil, the air the the bottle was heated.  Hot air expands, which made our balloon expand.  This is the same sort of principle that makes popcorn pop.  Little bits of water and air are inside an unpopped corn kernels.  When they are heated and the pressure builds inside the kernel, POP goes the corn.

We then talked about whether or not kernels that had been crushed with a hammer could pop.  After deciding they probably couldn't, I cut holes in our balloon and we heated the water and air inside the bottle again.  The balloon wasn't able to inflate because air pressure wasn't allowed to build up.  Therefore, a broken corn kernel can't pop because no pressure builds up.

Late last year, I Tivo'd a popcorn documentary on the History Channel that was the perfect afternoon viewing.  Of course, we ate popcorn!