Implications and Applications
- What is the coordination number for the center atom in the hexagonal close packing model?
- Why is the name face-centered cubic appropriate for this structure? Explain.
- Is the coordination number for the two types of close-packing of equivalent spheres different?
- How would the density of hexagonal close packing and face-centered cubic compare if both were constructed with spheres of the same size and mass?
- Metallic iron crystallizes in a body-centered cubic form below 906 °C. It's called alpha-ferrite. Above this temperature, iron forms face-centered cubic crystals, called gamma-ferrite. When iron cools to 140 °C, it changes back to body-centered cubic called delta-ferrite. What is the coordination number of each form of iron?
- Which ions most closely surround each Cl- ion? Which ions most closely surround each Na+ ion?
- What is the coordination number of the spheres representing Na+ ions? What is the coordination number of the spheres representing Cl- ions?
- What is the coordination number of the spheres representing both the Zn2+ and the S2- ions?
Activity 2 was adapted from Experiment 27, pp. 72-74, in the following source:
Malm, Lloyd E. (Ed.). (1963). Chemistry: An experimental science. Laboratory manual. San Francisco: W.H. Freeman and Company.
Chemical Bonding (BOND)
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