MSE 201 MIDTERM EXAM / 100 QUESTIONS AND ANSWERS / UPDATED VERSION 2023/2024

MSE 201 MIDTERM EXAM / 100 QUESTIONS AND ANSWERS / UPDATED VERSION 2023/2024 2 / 18 1. The atomic packing efficiency of tungsten (W) is72% 52% 68% 74% ANSW 68% 2. The crystal structure of copper isFCC BCC HCP Orthorhombic: FCC 3. Alkali metals,such as Li, Na and K, have BCC crystal structureTrue False: True 4. The planar density of (111) plane in FCC is about0.1 0.5 0.9 0.7: 0.9 5. The linear density along [110] direction in FCC is0.1 1.0 0.5 0.8: 1.0 6. The alpha-titanium (HCP) and beta-titanium (BCC) are two........................................................................of titanium. isotopes isomers polymorphs enantiomorphs: polymorphs 7. The crystal structures of alpha-Fe and delta-Fe are the same (i.e. BCC) buttheir lattice constants differ. True False: True 8. The crystal structure ofThO2 (thorium di-oxide or thoria) is TiO2-type. MoSi2-type. 3 / 18 NiH2-type. CaF2-type.: CaF2-type. 9. The effective number of atoms in an FCC unit cell (Al, Cu etc.) is8 4 2 6: 4 10. The body diagonals <111> of the BCC unit cell represent the close-packeddirections with a linear density of 0.7. True False: False 11. According to Hume-Rothery's rules, in a substitutional solid solution thesize difference between the solvent and the solute atoms must be within 50% 8% 51% 15%: 15% 12. A metal has a crystal structure of BCC type.The lattice constant is givenas 2.87 Angstrom (1 Angstrom = 10-10 m) and atomic mass of 55.85 amu (1 amu = 1.6610-27 kg).Then the theoretical density of themetal in g/cm3 is about 7.8 19.1