The third science session, on August 5th, focused on acids and bases. I should have planned more activities because we were done in 45 minutes. I also figured out that 1 hour is probably the right length for this kind of program instead of an hour and a half. 12 children attended, so a decent number.
This was also the session where I asked if there was any interest in science programs during the school year. Based off their responses, I’m going to give it a go. Art bots in October on a Tuesday evening.
We started the session with the “school” part. What acids/bases are –
acids: citrus: sour taste
bases: soap: taste bitter: feel slippery
The pH scale, indicators to tell where a substance is on the pH scale, and what chemical reactions are.
1. Foam at the Mouth – My husband introduced me to this a couple years ago, and it was a hit with my daughter (not so much my Girl Scouts when I did it with them). It was also a hit this time. I made extra packets for several of the children to take home to show their parents.
Recipe: equal parts citric acid, baking soda, and powdered sugar. Maybe 1/2 to 1 teaspoon of each. A little foams a lot. A cup of water to clear out the taste when the reaction is finished.
The citric acid and baking soda react when saliva is added (make sure to have the children take a swig of water first to wet their mouths, it will increase the amount of foam). The powdered sugar helps with the taste. I put the mixture in larger plastic cups so they could double as foam holders. Towards the end, it will taste salty (acid/base reactions create salt).
2. Acid or Base? – I made red cabbage litmus papers and chose 3 acids (vinegar, pickle juice, soda) and 3 bases (dish soap, conditioner, antacids) for the children to test. I thought about printing up a results sheet so they could write down observations and attach the litmus papers to, but I did not. This activity took all of 5 minutes, which was incredibly short given how long it took me to prep it.
3. Baggie Bombs – I used the instructions from Science Bob. We ended up doing it twice (increasing both vinegar and baking soda the second time) because the children absolutely loved it. Make sure to use slider-closing baggies.