. Copper (Cu) has FCC crystal structure. Atomic mass of Cu is 63.55 gmol-1 and radius of a copper atom is 0.128 nm, mean speed of conduction electrons in Cu is 1.5 × 10 and frequency of vibration of the Cu atoms at 27 ° is 4 × 10. Nordheim’sCoefficient of Au in Cu is 5500 Ω − . a) Calculate the atomic density of copper b) Estimate the drift mobility of electrons in Cu c) Find the resistivity of pure Cu d) Find the resistivity of Cu if 1 at.% of Au is mixed in Cu