Question

Which of the following statements is correct for a two-dimensional haxagonal close-packed layer?
A. Each sphere is surrounded by six spheres
B. Each sphere is surrounded by six voids
C. Each sphere has three voids
D. Each voids is surrounded by three spheres

Answer 1

Correct Answer - A::B::D

a. Each sphere is surrounded by six spheres.
b. Each sphere is surrounded by six voids.
Effective number of atoms in a hexagonal unit cell
`= ((1)/(3) xx 6) xx (1 xx 1) = 3`
Effective number of voids in a hexagonal unit cell `= 6`
Hence, each sphere has two voids.
d. Each voids is surrounded by three spheres.