You are given a small bar of an unknown metal, X. You find the density of the metal to be 11.7 g/cm3. An X-ray diffraction experiment measures the edge of the unit cell as 5.12 angstroms. Assuming the metal crystallizes in a face-centered cubic lattice, what is the atomic weight of X in g/mole? (1 angstrom = 1 x 10^-8 cm)

Answer 1

edge unit cell = 5.12E-8 cm
volume unit cell = edge^3
mass unit cell = volume x density = ?
Substitute into
? mass = 4atoms/unit cell x atomic mass/6.022E23
Solve for atomic mass.