Silver crystallises in an FCC lattice. The edge length of its unit cell is and its density is . What — Solid State Chemistry Question

💡 Solution & Explanation

Density $d = \frac{Z \times M}{N_A \times a^3}$. For FCC, $Z = 4$. Rearranging for molar mass $M$: $M = \frac{d \times N_A \times a^3}{Z} = \frac{10.5 \times 6.022 \times 10^{23} \times (4.07 \times 10^{-8})^3}{4}$. Calculating this yields $M \approx 107.9\text{ g mol}^{-1}$, so the atomic mass is $107.9\text{ u}$.