A certain solid mixed oxide crystallising in the cubic system contains cations `M_(1) and M_(2)` and the oxide ion `O^(2-)` Each `M_(1)` ion is surrounded by 12 equidistant nearest neighbour oxide ions. If the oxide ions occupy face centers of the cubic unit cell, where are the `M_(2)` ions situated ?

Options

A. At the center of the until cell
B. At the corners of the cube
C. At the edge centers
D. Occupying half the number of edge centers

Answer

B

Explanation

`M_(1)` is situated at the corners then `O^(-2)` ions at the face centres then C.N of `M_(1)` 12 equidistance neighbour oxide ions.