March 11, 2017
The chemistry unit fell on St. Patrick’s Day, and, boy, did we use a lot of green food dye! Making a mess (and cleaning up afterwards) is part of hands-on chemistry activities. We had lots of towels handy and let the children have fun. We began with an introduction to safety. At the first table, our science volunteer presented cups with clear liquids (water, vinegar, mineral oil and hydrogen peroxide), and reminded the students that not all that looks like water is water and that it is highly important to know the ingredients you are working with. At the second table, the children mixed their own solutions of sugar, salt and sand in water. They made Ooze (https://www.exploratorium.edu/science_explorer/ooze.html) and enjoyed its textured quality. The adult volunteer answered questions about solubility and viscosity. At our third table, kids mixed vinegar and baking soda (and some green dye, of course) and oohed at the bubbling chemical reaction. For encore, our volunteer presented the chemical reaction “Elephant Toothpaste” (https://sciencebob.com/fantastic-foamy-fountain/) to the sheer delight of our students. At table four,kids took notes of the color changes when baking soda (base) or vinegar (acid) were added to cups with cabbage juice. Kids used pH indicators to test the acidity of lemon juice, dish soap, salty water, and other liquids.
Vocabulary: Chemical reaction, solution, non-Newtonian fluid, acid, base.