Answer the following questions in a separate paper. Please show all your work to get full credit. Total points 15 1. Argon crystallizes in the face-centered cubic arrangement at 40K. Given that the atomic radius of Argon is 191pm. Calculate the density of solid Argon. 2. Metallic iron crystallizes in a cubic lattice. The unit cell edge length is 287pm. The density of iron is 7.87g/cm3. How many iron atoms are within a unit cell? 3. Lead crystallizes in a face-centered cubic unit cell with an edge length of 495pm. What is the radius of a lead atom in picometers? What is the density of lead in g/cm3