Q.1 The metal niobium has a BCC crystal structure. If the angle of diffraction for the {211} set of planes occurs at 75.99 degrees (for the first-order reflection, n=1) when monochomatic x-ray radiation having a wavelength of 0.1659 nm is used, compute
(a) the interplanar spacing (d) for this set of planes,
(b) the atomic radius for the niobium atom.