In Lesson 11, students review, analyze, and discuss the information they have collected to help identify the five unknown solids. In the next lesson, students compare this information to a Chemical Information Sheet, a reliable source of outside data, to discover the unknowns' identities at last. A reading selection illustrates the important role these and other chemicals play in students' everyday lives. Then, in Lesson 13, students articulate the process they have used to solve their mystery and apply their testing, observing, recording, and analyzing skills to a new situation. Lesson 14 challenges students to go a step beyond identifying one unknown solid as they perform a chemical analysis on a mixture of two unknown solids.
Students then apply their new knowledge to the five solids they investigated earlier.
Finally, Lesson 16 is an embedded assessment of the skills students have been developing throughout the unit. As students become more aware of the chemicals in their world, they are likely to have a number of questions that cannot easily be answered. It is a good idea to remind them that our knowledge of chemistry is always growing and changing. What you can do is help students learn how to continue to find out for themselves.