Constructing a revised

11.B Construct an explanation using models of the molecular structures of different substances to predict which gas must be produced (effect) in the bath bomb reaction based on the types of atoms that make up the substances (patterns), and use it to explain what is happening to the particles (matter) in the system to cause the production of this new substance.

11.B Construct an explanation using models of the molecular structures of different substances to predict which gas must be produced (effect) in the bath bomb reaction based on the types of atoms that make up the substances (patterns), and use it to explain what is happening to the particles (matter) in the system to cause the production of this new substance.

Students should be able to argue this by connecting the molecular models from Molecular Models of Different Substances. On this handout they can compare the atoms in baking soda, citric acid, and water to the three gases we had identified as possibly being produced (argon, methane, and carbon dioxide). Using the new key model idea around chemical reactions, students should be able to argue the only possible gas it could be is carbon dioxide.

If students are struggling with these ideas, they have an opportunity to compare their predictions and explanations with their small group at the start of the next lesson. Provide feedback to those students in the form of comments or notes that direct them to compare their responses to their peers and to resolve any differences.

Give students the remaining time to work on their responses. Collect Constructing a revised explanation from students before they leave.