1. Chapter 13 The Chemistry of Solids

2. Types of Solids Metals Network Ionic Molecular Amorphous

3. Chapter 13 The Chemistry of Solids Types of SolidsExamples MetalsCopper NetworkQuartz IonicNaCl MolecularCO 2, CI 4 Amorphousglass, polyethylene

4. Chapter 13 The Chemistry of Solids Types of SolidsCharacteristics MetalsCopper - malleable NetworkQuartz – non-malleable MolecularCO 2, CI 4 – low melting pt Ionic &muscovite– cleaves easy Network, Layered structure

5. Table 13.1 Study this!

6. The Chemistry of Solids What characteristic do these solids share?

7. The Chemistry of Solids What characteristic do these solids share? Repeating Structural Pattern other terms : Lattice Array Crystal Structure or Crystal Lattice

8. The Chemistry of Solids What repeats? Simplest Repeating Pattern: UNIT CELL is the smallest piece of the pattern that generates the lattice. in 2 D — wallpaper or Escher in 3 D — crystal structures

9. The Chemistry of Solids UNIT CELL is a conventional choice. May have several unit cells possible, Different in shape and/or size. Translation directions

10. The Chemistry of Solids UNIT CELL is a conventional choice. May have several unit cells possible, Different in shape and/or size.

12. Is this a good unit cell?

13. YES! This Unit Cell generates entire pattern by translation ONLY

14. Is this 2 nd cell a good unit cell?

15. Is this 2 nd cell a good unit cell? Yes! It also generates the pattern by translation.

16. 2 nd cell is larger: contains 2 white fishes 1st cell is smaller: contains 1 white fish

17. 2 nd cell is centered: contains 2 white fishes 1st & 3 rd cell primitive: contains 1 white fish

20. m m m m One C4 and 2 types of mirrors = 4m

21. Asymmetric Unit = smallest piece that generates entire unit cell

22. Cubic Unit Cells (highest symmetry) Tetragonal Cells Triclinic cells Monoclinic cells (lowest symmetry) Orthorhombic Cells Hexagonal Cells

23. Cubic Unit Cells have a = b = c  = 90 deg a c b

24. Three Types of Cubic Unit Cells a c b Simple Cubic Body Centered Cubic Face Centered Cubic

25. These Three Cubic Unit Cells are Structures of most Metallic Elements (also hexagonal, hcp, to be seen Friday) Cu, Ag, Au are all fcc Cr, Mo, W are all bcc Only Po is simple cubic ( rare— why? ) Simple Cubic Body Centered Cubic Face Centered Cubic

26. What is one result of a metal’s “choice” to adopt a cubic, bcc or fcc lattice? Simple CubicBody Centered CubicFace Centered Cubic

28. Primitive cell

32. Asymmetric unit = smallest portion needed to create unit cell 2 Asym./cells