However, the girls really had blast with this activity that we did the week of Halloween. All you need for this activity is cornstarch, water, alka seltzer, and a container with a lid to put it in. We painted ours like a ghost.
Seeing our ghost fly was just a fun experiment and I talked about the chemical reaction that was happening with the built up pressure in the container to where it had to explode! I think the girls enjoyed this.