Q. The radius ratio in is . The expected lattice structure is

 1822  220 UPSEEUPSEE 2008 Report Error

Solution:

The ratio of the radius of the cation to the radius of the anion is called radius ratio. From this ratio the structrue of lattice can be determined by using the following table
Arrangement
Planar triangular
tetrahedral
Octahedral
Body centred cubic

Here, the radius ratio of is , hence its lattice structure is body-centred cubic