1.16 When the principal quantum number n=1,1 subshell must be equal to zero, and an electron in this state would be designated by the symbol 2 s. True False 1.17 The Intercepts 1,1,, in a hexagonal unit cell correspond to the Miller-Bravais indices [1010]. True False 1.18 At some stage of production the majority of metals and alloys are melted and then allowed to solidify as a casting. Thus, solidification conditions determine the structure, homogeneity and soundness of cast products. True False 1.19 The transition from a highly-disordered liquid to an ordered solid is accompanied by a lowering in the energy state of the metal and the release of thermal energy (latent heat of solidification). True False 1.20 Crystal defects take the form of point defects (such as vacant atomic sites), Line defects (dislocations), planar defects (stacking faults) and volume defects (voids). True False