The lengthof a unit cell in the NI Crystal is 0.352 nm. The diffraction of X-rays of 0.154 nm wavelength (lambda) from a Ni crystal occurs at 22.2^(@), 55.9^(@) and 38.2^(@) . By using Bragg's law, (nlambda=2d "sin"theta) , and assuming that the diffractions are first order (n=1), the distance are calculated to be 0.204 nm , 0.176 nm and 0.124 nm The various structures for the Ni crystal are represented as: The distance (d) of 0.176 nm represent which structure?

The lengthof a unit cell in the NI Crystal is 0.352 nm. The diffractio

1.	The lengthof a unit cell in the NI Crystal is 0.352 nm. The diffraction of X-rays of 0.154 nm wavelength (lambda) from a Ni crystal occurs at 22.2^(@), 55.9^(@) and 38.2^(@) . By using Bragg's law, (nlambda=2d "sin"theta) , and assuming that the diffractions are first order (n=1), the distance are calculated to be 0.204 nm , 0.176 nm and 0.124 nm The various structures for the Ni crystal are represented as: The distance (d) of 0.176 nm represent which structure?
Answer» I II III All Solution :The DISTANCE 0.176nm is half the unit cell length (a/2) which CORRESPONDING to the perpendicular distance between the layers of atoms in ONE face of the unit cell and the CENTER (fig I).