In this Storyline, students develop an understanding of how to describe and classify materials by their observable properties. They design objects out of different materials and compare how well suited the materials are for a particular purpose. Students discover that an object made up of pieces can be disassembled and rearranged into different objects that have new properties and purposes. Finally, students investigate whether the properties of materials change when exposed to heat or cold and then use evidence to make an argument about the effects of heating and cooling.