Question

AgI crystallizes in the ccp, zinc blende structure. Assuming that $I^{⊝}$ ions occupy the lattice points, the fraction of tetrahedral voids occupied by $A{g}^{+}$ ions is :

• A. $10\%$
• B. $40\%$
• C. $50\%$
• D. $20\%$

Answer 1

The correct option is C $50\%$

In Zinc Blende structure,
anions are present at the lattice points while cations $A{g}^{+}$ are present in alternate tetrahedral voids and therefore the fraction of tetrahedral voids occupied by $A{g}^{+}$ ions is 50%.