Below is an electron micrograph of a colloidal crystal. This structure is comprised of close- packed...

 

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Below is an electron micrograph of a colloidal crystal. This structure is comprised of close- packed layers of glass particles. Alil the particles are identical and have a diameter of 1000 nanometers. Close examination of the micrograph indicates that the particles stack in an ....ABCABC... manner. (a) What is the crystal structure, basis, and lattice parameter (in nanometers) of this crystal? (b) Calculate the packing fraction occupied by the spheres. Note: you must derive your result. You cannot just write down the answer. (c) Estimate the density of the colloidal crystal. Assume that the glass spheres have a density of 2g/cm?. (d) To perform diffraction on this structure, one must increase from 0.15nm, the x-ray wavelength used for atomic crystals, to 1000nm. Why? (e) Assuming 2 is 1000nm, at what angle would you expect the lowest angle diffraction peak to appear? Below is an electron micrograph of a colloidal crystal. This structure is comprised of close- packed layers of glass particles. Alil the particles are identical and have a diameter of 1000 nanometers. Close examination of the micrograph indicates that the particles stack in an ....ABCABC... manner. (a) What is the crystal structure, basis, and lattice parameter (in nanometers) of this crystal? (b) Calculate the packing fraction occupied by the spheres. Note: you must derive your result. You cannot just write down the answer. (c) Estimate the density of the colloidal crystal. Assume that the glass spheres have a density of 2g/cm?. (d) To perform diffraction on this structure, one must increase from 0.15nm, the x-ray wavelength used for atomic crystals, to 1000nm. Why? (e) Assuming 2 is 1000nm, at what angle would you expect the lowest angle diffraction peak to appear?