Use the data in T

(a) The electrical resistivity of iron is . And, the electrical resistivity of mercury is . Since the resistivity of mercury is greater than that of iron, it will offer more hindrance to current flow as compared to iron. Therefore, iron is a better conductor than mercury.

(b) Silver metal has the lowest resistivity nearly about 1.60 x 10^-8m. Therefore, silver metal is the best conductor of electricity.