In this unit, Transformation of Matter, students study the transformations of materials and substances. By comparing the characteristics of the materials, such as color and physical state before and after a transformation, students learn that a transformation implies the modification of the final system in relation to the initial system.
In Lesson 1, students study the initial and final characteristics of systems and objects that undergo transformations. In Lesson 2 they melt flaked paraffin and solidify it in a new shape that the change of physical state does not necessarily modify the composition of some substances. Lesson 3 has students observe the process of water evaporation and material transformation through multiple experiments. In Lesson 4, by mixing water, flour, oil, and salt, students create a recipe for modeling dough. They discuss and define the necessary quantities and procedures so that the product has the desired characteristics (malleable, able to hold a shape). Then, they analyze specific properties of the new material after the transformation.
In Lessons 5, 6, and 7 the students compare and contrast physical and chemical changes by performing experiments that result in new substances or materials. After making glue with casein from milk, the experiment performed in Lesson 8, students discuss how multiple derivatives can be produced from a single product. They investigate the adhesive power of this glue and reach the conclusion that this property is another indication of the occurrence of a chemical change.
In Lessons 9 and 10 students work with the properties of a new material, dye. In Lesson 9 they learn that pigments can be natural or synthetic and they observe one of the first pigments synthesized by human beings. In Lesson 10, using the casein glue they made in a previous lesson, students mix a pigment, a solvent, and an agglutinant, all of which are necessary to fix the dye to the painted surface. During Lessons 11 and 12 students observe the rust formation process by doing an experiment where samples of steel wool are placed in different solutions.
Lesson 13 challenges students to consider raw materials used to make various products. Students recognize that chemical and physical transformations can make it difficult to identify the original state of matter. Lessons 14 and 15 have students discuss the care, use, and value of natural resources, as well as the production of garbage created by a consuming society, which ultimately threatens such resources. Students produce recycled paper and compare properties of different papers. Students also experiment with the effect of different additives used by the paper industry. In Lesson 16, the unit ends with students creating a game to challenge other teams on the knowledge acquired throughout these 16 lessons.