Question

In a body-centered cubic structure, every atom (except those on the surface) has eight neighbors. Which arrangement of balls serves as the best model for this structure? A)eight balls at the corners of a cube B)eight balls at the corners of a cube, and one ball in the center of the cube C)eight balls arranged equally apart from each other around a circle D)eight balls at the corners of a cube, and six balls in the centers of the cube’s faces

Answer 1

Answer : The correct option is (B).

Explanation :

Body-centered cubic structure (bcc) :

Crystal structure : The manner in which the atoms or ions are spatially arranged.

In bcc arrangement, the atoms are present at eight corners of the cube and at the center of the cube. And the coordination number is 8.

Each unit cell has $8\times \frac{1}{8}$ atoms at the corner and 1 full atom at the center of the cube.

Therefore, the each unit cell has $(8\times \frac{1}{8})+1=2$ atoms.

Image of bcc structure is shown below.

Answer 2

Answer: D. Eight balls at the corners of a cube, and six balls in the centers of the cube’s faces.

Explanation: