Question

Which of the folllowing statements is incorrect regarding diamond?
A. Each `C` atom is tetrahedrally surrounding by four other `C` atoms, each at a distance of `154 p m`
B. The tetrahedra are linked together into a three-dimensional giant molecule.
C. The unit cell has a body-centered cubic structure.
D. Strong covalent bonds extend in all directions.

Answer 1

Correct Answer - C
In normal diamond, the arrangement of the tetrahedra is the same as that in the face-centered cubic `ZnS` (sphalerite) ionic structure. There is also an extremely rare form Lonsdale in which the tetrahedra are arranged differently to give a `ZnS` wurtzite-like structure and a hexagonal unit cell.