Question

The number of tetrahedral and octahedral void per unit cell of cubic closed packed structure is

• A. 4, 8
• B. 4, 4
• C. 8, 4
• D. 8, 8

Answer 1

Answer: (C)

In ccp or fee structure Number of lattice points
$(Z)=4$
$\because$ Number of octahedral voids = Number of lattice points
$\therefore$ Number of octahedral voids $=4$
and Number of tetrahedral voids $=2\times$
Number of octahedral voids
$\therefore$ number of tetrahedral voids $=2\times 4=8$