Three-dimensional Learning Progression In this final lesson of the unit, students have completed the inquiry and application sequences for the combustion of ethanol. The activities in the previous lessons were designed to walk students through a cognitive apprenticeship model of Establishing the Problem, Modeling, Coaching, and Fading. The results of the unit posttest will help you determine if your students are ready to move on to the final stage: Fading. After the Fading stage, students will be expected to carry forward concepts from this unit into future units. If the results from your posttest imply that a majority of your students are still struggling with certain concepts, it might be valuable to return to some of the main concepts they are struggling with before moving on to the next Carbon TIME unit. Key Ideas and Practices for Each Activity Activities 5.1 and 5.2 are the Coaching phase of the Application Activity Sequence, which provides students with important less-scaffolded practice with combustion. Students should take more responsibility for their work than in lesson 4, which included the Modeling phase. Students answer the Three Questions for burning methane using the Explanations Tool, coordinating accounts at the macroscopic and atomic-molecular scales. Macroscopic scale accounts (represented here by the Zooming into a Flame) include these components: the structure of the system (the flame in this case) and the movement of materials through the system; the location where chemical change takes place; the materials involved in the chemical change: the reactants going in and the products coming out. Atomic-molecular scale accounts include three different ways of representing chemical change: molecular models, with twist ties to represent units of energy, that students use to physically rearrange the atoms of the reactants into the atoms of the products; a chemical equation that shows how atoms are rearranged into new molecules in a compact way (but does not account for energy); the Explanations Tool, which provides a way for students to account for changes in matter and energy in writing but answering the Three Questions. Activity 5.3 provides students with additional important Foundational Knowledge and Practice (in the Application Activity Sequence) about the fundamental difference between organic and inorganic materials. These two types of material are different in terms of: Origins: All the living organisms on Earth (foods and fossil fuels) have organic materials and originated in living organisms; Chemical energy: Organic materials have more chemical energy; Molecular structure: Organic materials have C-C and C-H bonds. Activity 5.4 is the Fading phase of the Application Activity Sequence for combustion. It serves as formative assessment for you—you will be able to see how well they understood the ethanol example—and gives students additional practice explaining examples with less support than they had for ethanol and methane. Activity 5.5 includes summative assessment for the unit. You can track students’ progress by having them take the Unit posttest (identical to the unit pretest) and comparing the results of the two assessments. Key carbon-transforming processes: combustion Content Boundaries and Extensions
