5) An x-ray diffraction analysis of a crystal is made with a molybdenum target (λ = 0.711A°). If one of the interplanar spacings is 1.82A°, what is the angle of diffraction for this particular set of planes (assuming first order diffraction). n=1 d=1.82A° λ=0.711A° θ= ? nλ=2dhklsinθ θ=sin-11x0.7112x1.82 θ=11.3° 6) Sodium metal crystallizes in a body-centered cubic arrangement where the length of one edge of the unit cell is 4.24A. What is the closest distance between centres of adjacent sodium atoms? d=4.24A°x3 4 d=1.84A° 7) A crime investigator in a forensic sciences laboratory wishes to identify the makeup of some material evidence. He suspects that the material is actually a mixture of two pure substances. Outline a method by which you think these two substances might be identified.

A great way for the crime investigator to identify the makeup of the material evidence would be to use x-ray diffraction. Every crystalline material in the world has its own diffraction pattern unique to one another, which would cause for the best solution to the problem encountered by the crime investigator. Once the material is illuminated with monochromatic X-rays, the atomic lattice of the sample causes the x-ray beam to be diffracted to specific angles. Once completed the use of Bragg’s law allows us to identify the atomic spacing of the mystery material and from there we can compare the unknown material to a list of known materials in order to discover the makeup of the material evidence. X-ray diffraction is just one of numerous ways to discover the makeup unknown materials