Copper is a low resistivity metal material commonly used for electrical cables and vvires. The resistivity of single crystalline copper bulk material is 1.67X10-6 0 cm. Cu is FCC structure and the lattice constant is 0.361 nm. a. Calculate the free electron density (#[cm3) in Cu.

Note: each Cu atom contributes one free electron in the Cu crystal since Cu is in group IB b. Find the electron mobility in single crystal Cu c.

In practical applications we mostly use polycrystalline Cu cables and wires for low cost. To minimize resistivity, would you prefer to have larger grains or smaller grains in the Cu vvire'? Explain your choice.