Our last experiment from the Geology Rocks! book was on acid rain:
In just skimming the picture, I thought we were going to somehow sculpt a person to use as our guinea pig, but in reading the actual items needed, this was a piece of chalk…I don’t know about you, but my chalk-carving skills are not such that I could make such a 3D, sculpture-in-the-round version of a person, especially wearing a hat! Plus, this was obviously made from a chunky piece of sidewalk chalk and all we had on hand are the small pieces of colored chalk I use to write grocery reminders on our kitchen chalk board. So here is my masterpiece of paper clip carving:
See the face?? I scratched in some stick figure arms and legs, too, but you can’t see them from this view. The book said to use “any” chalk from your local hardware store, as long as it was made from gypsum. Well, I looked but there was no ingredient list on our box of chalk, so I figured we were good to go.
We mixed a little water with some vinegar to simulate the acid of acid rain. Once again, we were without a medicine dropper, so we improvised with a drinking straw:
After watching the chalk for a few minutes and seeing that nothing was happening, we poured the rest of the acid rain solution on the plate and waited.
Nothing. Apparently our chalk was not made from gypsum after all. Based on this experiment combined with trying to make our own chalk, I am making a mental note to stay away from chalk-based activities from here on out.