In this problem based lesson, students are led through a series of hands on activities to observe and test six substances in order to gather information about their physical and chemical properties. The tests are constructed as a structured inquiry in which the question under investigation is: “What is the effect of combining each of the six powders with______ (vinegar, water, iodine, or heat)?” The investigations are in service to a larger “problem” in which the students need to investigate a “Cookie Mystery.” In the Cookie Mystery scenario, the ingredients for the cookie recipe (the six powders) have been mixed and the students need to figure out how to identify the substances in the unknown mixtures.
The manipulations students will use during the inquiry portion of the lesson will provide observational data, which will be used in the problem based investigation. The information students will gather draws on prior knowledge of mixtures and solutions, physical and chemical changes, and the effects of heat on matter.
After gathering data during the structured inquiry investigations, students will apply the same physical and chemical tests to “mystery” mixtures in order to identify the components. They will use a logical “if…, then…” framework to apply knowledge they have gained through their initial investigations to make sense of the novel situation of identifying the components in the mixtures.
Download the Cookie Lesson Plan.