$(12,00$ Puanlar$)$

Ceramic compounds $AB$ and $AC$ both have the zinc blende crystal structure and are soluble in one another at all

concentrations. Determine the concentration in weight percent of $AC$ that must be added to $AB$ to yield a unit

cell edge length of $0\mathrm{.}5304nm.$ The densities of $AB$ and $AC$ are $4\mathrm{.}8\frac{g}{c}{m}^3$ and $4\mathrm{.}2\frac{g}{c}{m}^3,$ respectively. The atomic

weights of A$,$ B$,$ and C are $30,80,$ and $60\frac{g}{m}ol,$ respectively.