Mixtures and Solutions:  Students discuss their ideas about pure substances and mixtures. They apply these ideas in an inquiry in which they determine whether samples are mixtures or pure substances. They then investigate solutions as an example of one type of mixture. Solubility in water is identified as a characteristic property of matter. Students also conduct inquiries using filtration, evaporation, and chromatography. They investigate changes in volume and the conservation of mass during dissolving, as well as the effect of solutes on melting and boiling points. Students then design a standardized test for the effectiveness of nonaqueous solvents at removing stains. This part of the unit culminates in an assessment in which students determine some of the properties of the substances of a mixture.

Compounds, Elements, and Chemical Reactions:  Students discover that water can be split into its component elements by electrolysis. Students look at elements and read the information provided on a series of element cards to classify 25 elements using their characteristic properties. They then compare these groups with their positions on the periodic table. Students look at the formation of a compound by reacting a metal and a nonmetal. The reactivity of different metals and the conservation of mass during chemical reactions are also investigated. Part 3 assesses both the students’ measurement skills and their ability to apply the concept of conservation of mass to dissolving and phase change.

Anchor Activity:  This is a research project in which students investigate a simple manufactured object, from its function and history to the properties of the materials used to make it. Students conclude by giving an oral presentation and constructing an exhibit to present their findings.