Please state all assumptions and formulas. Thanks! :)

1. The unit cell of CsCl crystal is BCC as shown in the figure (Cst: dark spheres, CI: light sphere). (a) What are the Miller's indices for the two planes shown by shaded areas in the figure. (6) The ionic radii of Cst and Care 1.67 and 1.81 , respectively. (1 = 0.1 nm) Find a (the side of the unit cell), if atoms are assumed to be hard spheres that are closely- packed, such that the closest spheres are pressed against each other. How many Cst and Cl are present in each unit cell? What is the fraction of the unit cell volume filled with atoms (considering the a/2 volume of atoms as the volume within the hard spheres with above radii)? a/2 (c) Knowing that the atomic weights of Cst and Clare 133 and 35.5, respectively, calculate the density (g/cm) a 2 of CsCl in crystalline form. (Hint: Avogadro's number NA=6.02x102) is the number of atoms in one mole (weight of 1 mole = atomic weight in grams). (d) In contrast to CsCl, NaCl crystal has a different unit cell. Draw the schematic of the unit cell of NaCl crystal. Find a for NaCl if the ionic radius of Nat is 1.02 . a a X