Science: Weighing Carbon Dioxide

 We did a fun experiment last week, so I wanted to share it with you.  We're studying Chemistry this year.  The book we're using is Adventures with Atoms and Molecules by Robert C. Mebane and Thomas R. Rybolt.  It's a fun book.  Each experiment's title is a question about molecules or atoms.  The answer comes as the kids do the experiment.  We use household items.  I don't think I've once had to go out and buy stuff for our science experiments.  In fact I usually don't look at the experiment until the night before, and that's never been a problem.

So, last week we did experiment #8 in book one where the question was, do some molecules weigh more than other molecules?  The book had us make a balance by hanging a yard stick from the ceiling and attaching a paper bag at each end.  We then got a bucket and measured a cup of baking soda and added two cups of vinegar.  We were then instructed to wait for 30 seconds while the baking powder and vinegar bubbled and then....this is the cool part...pick up the bucket and pour the carbon dioxide gas into one of the paper bags of your balance.  Now, CO2 is a colorless odorless gas, so it's like you're pouring nothing out of the bucket.  And then as you start to do it the balance suddenly falls on the side you are pouring the gas into.  It's so cool!!!!  My kids loved it.  We had to do it a second time because it was so cool.

My kids totally understand why helium balloons float, because those molecules are lighter than air molecules.  Discovery learning using experiements can be so fun!