Final answer:
The coordination number of the Mn ion in a cubic unit cell with manganese ions at the corners and fluoride ions at the center of each edge is 6.
Step-by-step explanation:
The question pertains to crystal structures and the coordination number in a cubic unit cell containing manganese and fluoride ions.
To start with, a cubic unit cell that contains manganese ions at the corners and fluoride ions at the center of each edge would mean that each manganese ion (Mn) is surrounded by fluoride ions (F) located at the midpoints of the edges of the cube.
Each edge has two midpoints, and each midpoint is shared with an adjacent unit cell.
For a cube, there are 12 edges, and since each fluoride ion at the midpoint of an edge is shared between two unit cells, the total coordination for one manganese ion by fluoride ions is 6.
Therefore, the coordination number of the Mn ion is 6, making the correct answer C.