Why do Bragg reflection intensities differ for Cs, CsCl and CsI?

[captainjack2000]

Homework Statement

How would you expect the intensities of the Bragg reflections in the x-ray diffraction patterns of cesium, cesium chloride and cesium iodide to compare? (The atomic numbers of cesium, chlorine and iodine are 55, 17 and 53 respectively_

Homework Equations

The Attempt at a Solution

I am really unsure how to do this question at all. The first part of this question delt with structure factors so I know that the scattering intensity I=Io A (S)^2 where S is the structure factor. Not sure how this helps?

 

[aurora14421]

The structure factor is proportional to the number of electrons in the atom (or the atomic number if the atom is uncharged).