Metallic barium has a body-centered cubic structure (all atoms at the lattice points) and a density of 3.51 g/cm3. Assume barium atoms to be spheres. The spheres in a body-centered array occupy 68.0% of the total space. Find the atomic radius of barium. (See Problem 11.93.)
Problem 11.93
Metallic magnesium has a hexagonal close-packed structure and a density of 1.74 g/cm3. Assume magnesium atoms to be spheres of radius r. Because magnesium has a close-packed structure, 74.1% of the space is occupied by atoms. Calculate the volume of each atom; then find the atomic radius, r. The volume of a sphere is equal to 4πr3/3.