1. Learning targets 1.Students can describe how heat treatment of materials alone can change a material’s properties. 2.Students can shape Styrofoam balls into various crystal forms.

2. Sulfur Monoclinic (from a melt) Orthorhombic (from solution)

3. Amorphous Sulfur

4. Allotropes of Sulfur rhombicamorphous monoclinic

5. Why are Crystals Important? Discuss the following question at your tables and be prepared to share your answer. Have you ever had a experience where a material could change its behavior with different types of heat treatment?

6. Bedazzled!!!!! http://www.thatcrystalsite.com/downlo ads/NaicaCrystalCave.pps#257,1,Slide1http://www.thatcrystalsite.com/downlo ads/NaicaCrystalCave.pps#257,1,Slide1 –Giant crystals in cave in Mexico

7. Models of Crystals Lab Look for spacing (tightly vs. loosely packed – “gappiness”) Look for relative number of slip planes Try combining several examples of the same model into a bigger one

9. Simple cubic Face-centered cubic (FCC) Body-centered cubic (BCC) Hexagonal close packed (HCP)

10. Most Common Metal Crystal Structures BCC Body Centered Cubic FCC Face Centered Cubic HCP Hexagonal Close Pack

13. Ways to form Crystals From a solution as the solvent cools or evaporates –Growing single crystals –Sodium acetate demo –http://video.google.com/videosearch?q=sodium+acetate&hl=e n&sitesearch=#http://video.google.com/videosearch?q=sodium+acetate&hl=e n&sitesearch=#