We started with a CSI - inspired activity to discover who stole a missing cake. This lab had us testing known substances (baking soda, baking powder, powdered sugar and cornstarch) by adding drops of water, vinegar and iodine to each sample. We recorded our results (fizz, color change, etc.) and determined if they represented chemical or physical changes. Then each group was given an unknown substance to represent 3 suspects and the crime scene. The team with the suspect whose results were the same as those found at the crime scene caught the culprit.
We also learned all about acids and bases this week. We colored in a pH scale in our lesson books and learned that blood is close to 7 on the scale (close to neutral like water). It makes sense when you consider that all of our organs and tissues would be damaged if the pH of our blood was higher or lower. Then we got out lots of lovely test tubes and used red cabbage as an indicator to tell us which substances we tested are acids or bases. We tested Draino, coke, vinegar, milk of magnesia and about 8 more substances. The colors were so pretty!
Finally, we drew some beakers and blow-painted metallic paint to make it look like the fluids inside were bubbling, or in some cases, exploding!
