1. Electrical and thermal conductivity of In Electron drift mobility in indium has been measured to be 6 cm² V^-1 s^-1. The room temperature (27 °C) resistivity of In is 8.37 ×10^-8 Ω m, and its atomic mass and density are 114.82 g mol^-1 and 7.31 g cm^-3, respectively.

a. Based on the resistivity value, determine how many free electrons are donated by each In atom in the crystal. How does this compare with the position of In in the Periodic Table (Group IIIB)?

b. If the mean speed of conduction electrons in In is 1.74 ×10⁸ cm s^-1, what is the mean free path?

c. Calculate the thermal conductivity of In. How does this compare with the experimental value of 81.6 W m^-1 K^-1?