EVALUATION

This chapter-end exercise checks the full span of Unit 6. The 23 'Choose the Best Answer' multiple-choice questions cover: distinguishing covalent, ionic, molecular and metallic solids and correctly classifying named substances; unit cell theory including primitive vs non-primitive cells, the seven crystal systems, and counting atoms per cell in sc/bcc/fcc; packing-efficiency and packing-geometry numericals for simple cubic, body-centred cubic and face-centred cubic structures (including deriving radius-edge relationships and computing edge lengths, densities and vacant space); the radius ratio rule and coordination number in ionic structures such as NaCl and CaF2; and all four point-defect types (Schottky, Frenkel, metal excess and metal deficiency), including their effect (or lack of effect) on density and their role in phenomena such as the yellow colour of heated NaCl. …