Materials Needed: balloons (filled up about 2/3 of the way worked best), vegetable oil, wooden skewers, Sharpie
Comments: This is super cool. It feels like a magic trick. It took a few tries to get it, but for those who were brave enough to try (and didn’t mind the noise when it didn’t work out), it was very rewarding. We let the 3rd to 5th graders try this out, and they all wanted to show it to their parents when they came in to pick them up. We don’t always do a lot of explaining in this program, but we talked about how it works (low stress on the top and bottom of the balloon) and drew dots on the balloon with a Sharpie to show the increased stress/stretching across the middle. All of the kids were able to explain how it worked to their parents.
Table 1: Blow up Balloons with Chemistry!
Materials Needed: empty water bottle, vinegar, baking soda, balloons, Sharpie, measuring cups/spoons, funnels
Comments: We did a demo first using 1/2 c vinegar and 1 T baking soda. Then we let the kids decide what amounts they wanted to try.
The 3rd to 5th graders were pretty independent in making reasonable choices and carrying out the experiments. We had a few close calls with pretty vigorous reactions (I was afraid the balloons would shoot across the room and we’d get vinegar everywhere), but by holding the neck of the balloon firmly while the reaction took place, we were able to keep everything contained. I wouldn’t go over 2/3 c vinegar and 2 T baking soda, though.
We didn’t have enough funnels to pour the vinegar into the bottles and get the baking soda into the balloons, so we did use some home made paper funnels to fill the balloons. The kids were pretty good about keeping the baking soda in the balloon until the balloon was firmly on the neck of the bottle, but I can imagine some pretty impressive oopsies if the baking soda was dumped too soon.
We also considered blowing up balloons with Coke and Pop Rocks, but there was something cooler about doing it with materials that didn’t inherently fizz.
Table 2: Static Butterflies
Materials Needed: construction paper, tissue paper, glue, balloons
Comments: We used this at Hands On Science with the preschoolers in the fall. For them, we had the butterflies already made and just played with the balloons to make the wings flap with static. With the 3rd to 5th graders, we precut the pieces but allowed them to make and decorate the butterfly. This didn’t have the wow factor of the other activities, so the kids might have liked it better if we had done it first.
Table 3: Balloon Rockets
Materials Needed: string, tape, straws, scissors, balloons
Comments: We ran out of time before we got to this one.