Jonathan and I have been reading a book this past week called Gus and Grandpa and Show-and-Tell by Claudia Mills. I think the Gus and Grandpa books are quite good, and this one was no exception. One of the show-and-tell projects mentioned was a science experiment: creating a gas out of vinegar and baking soda and blowing up a balloon. Jonathan was fascinated and I realized that I had those very simple ingredients on hand and could do it with him!
It didn't exactly blow up the balloon, but it filled up with enough gas to make it stand up straight and feel firm when squeezed. The boys thought it was extremely awesome, although they weren't all that interested in the science of gases! Well, that will come when they're older. For now, I'm glad we can do "science projects" with such joyous reactions!
To re-create the experiment, you'll need:
a narrow-neck bottle
1 t. baking soda
2 T. vinegar
Put the soda inside the bottle. Add the vinegar and cover the bottle top with the balloon as quickly as you can.
Be advised that if you try using extra soda and vinegar in an attempt to get more gas, you will probably end up with foaming bubbles all over your table and hands. Not that I would know from experience or anything, of course.