The density of a cubic crystal is given by:
- $\rho = nM/(a^3 N_A)$
- $\rho = a^3 N_A/(nM)$
- $\rho = nM \cdot a^3 \cdot N_A$
- $\rho = M / a^3$
Show answer and solution
Correct answer: A. $\rho = nM/(a^3 N_A)$
Density $\rho$ = mass/volume = $(n \times M/N_A)/a^3 = nM/(a^3 N_A)$, where $n$ = particles per unit cell, $M$ = molar mass, $a$ = edge length, $N_A$ = Avogadro's number.