Question

A crystal is made of particles A and B . From fcc packing and B occupies all the octahedral voids . If all the particle along the plane as shown in figure are removed , then, the formula of the crystal would be :

A. AB
B. `A_(5)B_(7)`
C. `A_(7)B_(5)`
D. `None of these

Answer 1

Correct Answer - A
In new arrangement A particles `= ((1)/(8) xx 8 + (1)/(2) xx 6) - ((1)/(8) xx 4 + (1)/(2) xx 2) = (5)/(2)` & B particles `= ((1)/(4) xx 12 + 1) - (1 + (1)/(4) xx 2) = (5)/(2)`
So, formula is AB