The ratio of **tetrahedral voids** to **atoms** in a close-packed structure (fcc or hcp) is:
- 1 : 1
- 2 : 1
- 1 : 2
- 3 : 1
Show answer and solution
Correct answer: B. 2 : 1
In any close-packed structure (fcc/hcp), per atom in the lattice there are 2 tetrahedral voids and 1 octahedral void.
Used in classifying ionic compounds (NaCl fcc lattice, etc.).