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1 Calculate the lattice parameter of each of the following elements using their atomic radi (a) chromium, (b) nickel. 2. Calculate the atomic radius in cm for the following: (a) BCC metal with ao = 0.3294 nm; and (b) FCC metal with ao = 4,0862 A. 3. Calculate the theoretical density of silver given that it is FCC, has a lattice parameter of 4.0862 A with an atomic weight of 107.868 g/mole. Compare your value to the density derived experimentally for silver. Why is there a difference? Explain. 4. The density of potassium, which has the BCC structure, is 0.855 g/cm³. The atomic weight of potassium is 39.09 g/mol. Calculate (a) the lattice parameter, and (b) the atomic radius of potassium. 5. A metal having a cubic structure has a density of 2.6 g/cm³, an atomic weight of 87.62 g/ mol, and a lattice parameter of 6.0849 A. One atom is associated with each lattice point. Determine the crystal structure of the metal. 6. Beryllium has a hexagonal crystal structure, with a = 0.22858 nm and co= 0.35842 nm. The atomic radius is 0.1143 nm, the density is 1.848 g/cm³, and the atomic weight is 9.01 g/mol. Determine (a) the number of atoms in each unit celt; and (b) the packing factor in the unit cell.
7. Determine the indices for the directions shown in the following hexagonal unit cell (Figure 1): Du 03 ੪॥ a (B) (d) (c) Figure 1 (a-d): Hexagonal unit cell 13 14 Marks
8. Determine the Miller indices for the planes shown in the following unit cell (Figure 2): -+y B Figure 2 [2 marks]
9. Determine the Miller indices for the planes shown in the following unit cell (Figure 3): +2 ~/3 1/2 B Figure 3 112 ---- [2 marks]
10. Determine the Miller indices for the planes shown in the following unit cell (Figure 4) B ty Figure 2 [2 marks]