Lithium has a bcc structure. Its density is 520 kg m–3 and its atomic mass is 6.94 g mol–1. Calculate the edge length of a unit cell of Lithium metal. (NA = 6.02 × 1023 mol–1) (NEET 2016)

Density= 3 3 530 / 0.530 / Kg m g cm Atomic mass M = 6.94 g/mol For bcc unit cell the number of atoms per unit cell Z =2 3 3 23 3 23 8 12 2 6.94 0.530 6.023 10 4.34 10 3.52 10 352 10 352 A ZM density a N a a a cm m pm x x x x x x Hence the correct answer is option (b) 37. Which is the incorrect statement ? (NEET 2017) (a) Density decreases in case of crystals with Schottky defect. (b) NaCl(s) is insulator, silicon is semiconductor, silver is conductor, quartz is piezo electric crystal. (c) Frenkel defect is favored in those ionic compounds in which sizes of cation and a