Question

Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are :

• A. $12,6$
• B. $8,4$
• C. $6,12$
• D. $2,1$

Answer 1

The correct option is A $12,6$

• Number of octahedral and tetrahedral voids formed by $N$ closed packed atoms are $N$ and $2N$ respectively.
• Each hexagonal unit cell contains $6$ atoms therefore, number of tetrahedral and octahedral voids are $12$ and $6$ respectively.

Hexagonal Unit cell: