Question

A solid crystal is composed of X, Y and Z atoms. Z atoms (radius 200 pm) form cubic closed packed structure where as X (radius 50 pm) and Y (radius 100 pm) occupy respective voids. Assume all the voids are occupied.
Which type of voids are occupied by ‘x’ atoms:

• A. Tetrahedral
• B. Octahedral
• C. Cubic
• D. All of these

Answer 1

The correct option is A Tetrahedral

A solid crystal is composed of X, Y and Z atoms. Z atoms (radius 200 pm) form cubic closed packed structure where as X (radius 50 pm) and Y (radius 100 pm) occupy respective voids. Assume all the voids are occupied.
$\frac{r_x}{r_z}=\frac{50}{200}=0.25$
Which is in b/w 0.225 – 0.414
$\therefore$ ‘X’ atoms are in tetrahedral voids