Answer to Question #70117 in General Chemistry for Tequila Brown

Question

When 149-pm xrays are incident on a metal surface, a maximum diffraction angle of theta is equal to 28.5 degrees is produced. Assuming n=1, what is the separation between layers of metal atoms in this crystal lattice?

Answer 1

The distance between layers of atoms in the crystal lattice can be calculated from the maximum
diffraction angle according to the Bragg's law:
where d is the distance between layers of atoms, λ is the wavelength. The value of sinθ can be
found from mathematical tables: sin(28.5°) ≈ 0.4772. So, we can now calculate d:
Answer: the separation between layers of metal atoms in this crystal lattice is 156.12 pm.