Question

Which of the following figure represent the tetrahedral void?
(note: red spheres are placed over the layer of black spheres)

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Tetrahedral voids:
These voids are formed if sphere of second layer is placed over void of first layer. Connecting the spheres of the voids gives a tetrahedron shape, thus these voids are called tetrahedral voids or tetrahedral holes.

Option (b) represent octahedral voids, because the void connects to 6 spheres and the centres of the spheres are combined to form an octahedron.

In option (c), the void is two dimension and it connects to four spheres.

In option (d), the first layer spheres are not in contact so it does not form a void.