Question

Which of the following statements is/are correct about tetrahedral voids in an fcc unit cell? Given that the length of the edge of the unit cell is $a$ pm and of body diagonal is $b$ pm :

• A. Each tetrahedral void lies at a distance of $\frac{b}{4}$ from the nearest corner.
• B. Each tetrahedral void lies at a distance $\frac{3b}{4}$ from the farthest corner.
• C. Each tetrahedral void lies at a distance of $\frac{\sqrt{3}a}{4}$ from the nearest corner.
• D. The distance between two tetrahedral voids is $\frac{b}{2}$.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A Each tetrahedral void lies at a distance of $\frac{b}{4}$ from the nearest corner.
B Each tetrahedral void lies at a distance $\frac{3b}{4}$ from the farthest corner.
C Each tetrahedral void lies at a distance of $\frac{\sqrt{3}a}{4}$ from the nearest corner.
D The distance between two tetrahedral voids is $\frac{b}{2}$.

(A) Each tetrahedral void lies at a distance $\frac{b}{4}$ from the nearest corner.
(B) Each tetrahedral void lies at a distance $\frac{3b}{4}$ from the farthest corner.
(C) Each tetrahedral void lies at a distance of $\frac{\sqrt{3}a}{4}$ from the nearest corner
(D) The distance between two tetrahedral voids is $\frac{b}{2}$.

Hence, all statements are correct.