1. Long-term growth of crystals and comparison of crystal shapes.
2. Have students do a written or oral report on their birthstone. Identify its composition and the origin of the stone’s color (see References). Discuss the crystal system to which the stone belongs (see Figure 4). (Idea from Angie Matamoros.)
3. Concrete can be made in the laboratory and provides excellent practice in controlling variables. It is, however, a messy procedure, and students must be cautioned about spilling the ingredients on equipment and clothing and about pouring cement containing wastes in sinks. A convenient ratio is 14.5 g cement, 41g sand, 57g gravel, and 11.5 g water. Use disposable containers such as paper cups or coffee cans. The materials must be stirred while mixing and allowed to stand several days. The concrete can be analyzed, and other combinations may be tried. More complete instructions are available in the written materials accompanying "Chemical Kinetics" (Program 7) The World of Chemistry, High School Version, Wings for Learning, 1600 Green Hills Road, P.O. Box 660002, Scotts Valley, CA 95067-0002.
4. A Chemist’s Map of the United States -- Examine "A Chemist’s Map of the United States" (see the transparency master in the Appendix). List all cities that describe the solid state.
5. A Chemist’s Map of Your State -- Refer to a detailed Atlas of the United States, selecting your state map. Find and make a list of site names associated with chemistry. Prepare an outline sketch of your state map, situating the sites at appropriate points on the map.