Niobium (Nb) has the BCC crystal with a lattice parameter a = 0.3294 nm. Find the planar concentrations as the number of atoms per nm2 of the (100), (110) and (111) planes. Which plane has the most concentration of atoms per unit area? Sometimes the number of atoms per unit area nsurface on the surface of a crystal is estimated by using the relation nsurface = nbulk 2/3 where nbulk is the concentration of atoms in the bulk. Compare nsurface values with the planar concentrations calculated above and comment on the difference. [Note: The BCC (111) plane does not cut through the center atom and the (111) has 1/6th of an atom at each corner