Question

Which of the following best describes a tetrahedral void?

• A. combination of triangular voids
• B. space within a cube
• C. unoccupied space between $4$ spheres arranged in a tetrahedron
• D. space unoccupied between $6$ spheres

Answer 1

The correct option is C

unoccupied space between $4$ spheres arranged in a tetrahedron

Explanation for correct option

(c) unoccupied space between $4$ spheres arranged in a tetrahedron

• Unoccupied empty spaces are present in tetrahedral voids.
• When all these atoms and empty regions are arranges in tetrahedral crystal system.
• Thus these voids are called tetrahedral
• Hence, tetrahedral void is unoccupied space between $4$ spheres arranged in a tetrahedron.
• Therefore, the correct option is (c) unoccupied space between $4$ spheres arranged in a tetrahedron.

Explanation for incorrect options

(a) combination of triangular voids

• Triangular voids would be in triangular ($(3\mathrm{sided}\mathrm{figure})$ shape.
• Hence (a) combination of triangular voids is the incorrect option.

(b) space within a cube

• Cube is unit cells of a crystal lattice.
• So, space within a cube can not be a tetrahedral void.
• Hence (b) space within a cube is the incorrect option.

(d) space unoccupied between $6$ spheres

• Space unoccupied between $6$ spheres would be in hexagonal ($(6\mathrm{sided}\mathrm{figure})$ shape.
• Hence (d) space unoccupied between $6$ spheres is the incorrect option.

Hence, the correct option is (c) unoccupied space between $4$ spheres arranged in a tetrahedron