1. Objectives • Element abundances in the Earth
• Chemical bonds in crystals and their influence on physical properties
• Coordination polyhedra & Pauling’s rules
• Common structure types

2. Periodic table of elements
Klein Fig 3.22

3. What is the Earth made of?

4. What is the crust made of?
Klein Fig 3.2

5. Bond type and hardness diamond graphite
diamond
graphite

6. Ions: Charge and radius
Wenk & Bulakh

7. Coordination polyhedra
Klein22 Fig3.35

8. Ionic radius and C.N. Klein22 Fig3.31
Klein22 Fig3.31

9. Coordination number C.N.
Wenk & Bulakh

10. Electrostatic valency
+ 1/6 Na
Cl-

11. Sharing decreases stability

12. Close-packed structures
3 positions
A Sphere
B Void
C Void B C

13. Hexagonal close-packed structure - hcp

14. Hexagonal Close-Packed Structure - hcpB AB

15. Hexagonal Close-Packed Structure - hcpB
ABAB....

16. Cubic close-packed structure - fcc or ccp

17. Cubic Close-Packed Structure - fcc or ccpAB

18. Cubic Close-Packed Structure - fcc or ccp
ABC C

19. Cubic close-packed structure - fcc or ccp
ABC
ABCABC.... C

20. Cubic close-packed structure - fcc or ccp