A crystal is made up of particals `X`, `Y`, and `Z`. `X` froms `fcc` packing. `Y` occupies all octahedral voids of `X` and `Z` occupies all tetrahedral voids of `X`. If all the particles along one body diagonal are removed. Then the fromula of the crystal would be

Options

A. `XYZ_2`
B. `X_2YZ_2`
C. `X_8Y_4Z_5`
D. `X_5Y_4Z_6`

Answer

D

Explanation

When all particle along one body diagonal are removed, these 2X particles from corner are removed, one Y particle removed & 2 Z particle removed.
Hence new arrangement, X particle `=1/8xx6+1/2xx6=15/4`, Y particle =3,Z particle `=6`
Hence formula = `X_(15//4)Y_3Z_6=X_(5//4)YZ_(2)=X_5Y_4Z_8`