Make a list of questions you would need to ask in order to classify a solid into one of the categories of crystalline solids (molecular solid, ionic solid, nonbonded solid, metallic solid, and network covalent solid). Determine a good order to ask them. (You may need a branching decision tree.) Once you have agreed on a good set of questions, have each group member choose a substance from the chapter and then have the other group members ask the questions in turn until the correct classification is reached. You may agree to edit your questions if you discover ways to improve them when you are using your decision tree.