Respuesta :
The image attached below is the correct representation of a face-centered cubic unit cell model. To create this model, you have to place 6 balls in the centers of each of the cube's faces and 1 ball for every corner of the cube which sums up to 8 balls. Therefore, the answer is: eight balls at the corners of a cube, and six balls in the centers of the cube's faces.

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