A uni-univalment ionic crystal AX is composed of the following radii ( ar bitrary units) . {:( A^(+) , X^(-)),(1.0, 2.0):} Assuming that ions are hard spheres, predict giving reasons whether the crystal will have sodium chloride or cesium chloride structure.Calculate the volume of the unit cell.

A uni-univalment ionic crystal AX is composed of the following radii (

1.	A uni-univalment ionic crystal AX is composed of the following radii ( ar bitrary units) . {:( A^(+) , X^(-)),(1.0, 2.0):} Assuming that ions are hard spheres, predict giving reasons whether the crystal will have sodium chloride or cesium chloride structure.Calculate the volume of the unit cell.
Answer» Solution : ` r_(+)//r_(-) = 2//1 = 0.5` Which lies in the range 0.414 - 0.732 HENCE, it has sodium CHLORIDE struture. ( EDGE = ` 2 ( r_(+) + r_(-) = 6 "au"` . Volume =` ( 6 " au")^(3) = 216 ("au")^(3)`