Messin' with Mixtures

In this lesson, students will investigate the properties of a mixture, as if it were a contaminated soil sample near a stream. This activity will show students that heterogeneous mixtures can be separated by physical means, and that when separated, all the parts will equal the whole. Students will look at a heterogeneous mixture as if it were a contaminated soil sample to be cleaned up by environmental engineers. Students will separate the mixture by physical means. The plate of cereal mix is the “soil sample. This is a small sample of soil that was found outside of a construction site. Most soils are made up of many different small components. Some of the components in this soil sample are contaminants (Nitrates, lead, Mercury). Soil contaminants can have high health risks when we come in direct contact with the soil or when the contaminants break down into the surrounding ground water and into our water resources. As environmental engineers, students need to determine the percent of each material found in the soil sample. This will help to determine the level of risk to the surrounding water shed.