Gold crystallizes with FCC lattice for which the side length of the unit cell is 5.0 Å. If the densi — Solid State Chemistry Question

💡 Solution & Explanation

For FCC, Z = 4. M = 198 g/mol. a = 5.0 Å = 5.0 × 10^-8 cm. Density ρ = (Z × M) / (Na × a³) => Na = (Z × M) / (ρ × a³) = (4 × 198) / (10.5 × (5.0 × 10^-8)³) = 792 / (10.5 × 1.25 × 10^-22) ≈ 6.034 × 10^23.