X-ray production is very useful in a number of applications. Using high- speed electrons to knock other electrons off the inner shells of heavy- atom targets, x-ray machines produce "characteristic x-rays": high-energy photons with wavelengths in the x-ray spectral range. Typically the most abundant photons produced in this manner are Ka, Ke and La X-rays. Using the screening-model for many-electron atoms, calculate these three most abundant photon wavelengths for a target consisting of (a) Silver (b) Tungsten GGG (c) Molybdenum