When an electron in an excited atom of molybdenum relaxes from the L-shell to the K-shell, an X-ray photon is emitted. Diffraction of this light by layers of atoms 2.64 Å apart produces a first-order reflection at . Calculate the difference in energy between the L- and K-shells of the molybdenum atom.
X-rays of wavelength 0.5594 Å are diffracted by a face-centered cubic metal lattice. The radius of the metal atom is 1.345 Å. Calculate to, 3 significant figures, the diffraction angle of the second-order reflection ().
Platinum crystallizes with a face-centered cubic unit cell and diffracts X-rays of wavelength 1.541 Å to produce a second-order () reflection at . Calculate to 3 significant figures the density of platinum.