Calculate the lattice parameter (a) and the atomic radius (R) of the following material using the given information: potassium: BCC structure, density = 7.15 g/cm3, atomic weight = 51.3 g/mol. Round to at least three significant digits. You may also use scientific notation to enter your answer. For example, 0.00231 can be entered as 2.31e-3 or 23.1E-4. For power of the unit use (^), it means for writing cubic meter you can write m^3. (4)Calculate the lattice parameter (a)(cm). (4) Calculate the atomic radius (R) (cm)