show that the resistivity of intrinsic Ge at 300k is 44.44 ohm-cm. If donor impurity is added to an extent of 1 atom per 10^8 Ge atoms, prove that the resistivity of the Ge sample drops to 4.42 ohm-cm (at 300k). Assume that the electron mobility is 3800 cm^2/v*s, and the hole mobility is 1800 cm^2/v*s; ni=2.5x10^13 electrons per cm^3; and, number of G2 atoms per cm^3=4.41x10^22.