1. Calculate the packing fraction for a bcc structure

2. . In an ionic crystal of interpenetrating pc structure, show what the minimum cation to anion distance is. Explain why this is a minimum and not a maximum.

3. Cubic close packing occurs in fcc crystals. What fraction of the total volume is occupied by the atoms in a fcc crystal.

4. In an ionic crystal of interpenatrating fcc stucture, show what the minimum cation to anion distance is. Explain why this is a minimum and not a maximum.

5. Show that for an element that crystallizes in a body centered cubic structure that the atomic radius, r, is related to the length of the unit cell, a, by the equation:

a = 2.31 r