Some commercially available science units that deal with this topic. A simulated environmental problem is the focus of applying the steps of the scientific process. The problem is the mysterious appearance of a coating of white powder around the school yard. Students are challenged to identify the powder and its orgin. As they meet this challenge, they learn that systematic gathering, organizing, and analyzing of information are a way of coming to understand events in the natural world.
Students begin by focusing on the physical properties of color, form, and texture.
Next, they explore chemical properties by observing how the five powders interact with water, vinegar, iodine, and red cabbage juice. These tests enable them to explore phenomena such as crystallization and to observe the processes of evaporation and filtration. Finally, students apply their skills and their knowledge of the five chemicals to identify a variety of mystery mixtures. As a result of conducting these investigations, students develop scientific skills such as observing and recording results, forming conclusions on the basis of experience, communicating results, and applying their knowledge to solve problems. They measure, mix, and compare solids and liquids, and observe and describe the interactions that result from their experiments.