TABLE 3-1 ELECTRICAL CONDUCTIVITY AND LORENZ NUMBER FOR SOME METALLIC ELEMENTS' T=100K T=273K Metal Electrical Lorenz Electrical Lorenz Conductivity Number Conductivity Number (ohm-'m-') (volt/kelvin) (ohm-i m-) (volt/kelvin)2 σ L=(KeloT) L=(Ke/oT) Copper 2.9×10 1.9×10-8 6.5×10 2.3×10-8 Gold 1.6×10° 2.0×10-8 5.0×10 2.4×10-8 Zinc 6.2×10 1.8×10-8 1.8×10 2.3×10-8 Cadmium 4.3×107 2.1×10-" 1.5×10 2.4×10-8 Aluminum 2.110 1.5×10-8 4.0×10 2.2×10-8 Lead 1.5×10 2.0×10-8 5.2×10 2.5×10-8 Tungsten 9.8×10 2.8×10-8 2.1×107 3.0×10-8 Iron 8.0×10 3.1×10-8 1.1×107 2.8×10-8 Values for o are taken from G.T.Meaden,Electrical Resistance of Metals(Plenum Press,1965).Thermal conductivity data from American Institute of Physics Handbook (McGraw-Hill,3rd edition,1971)then permits calculation of the Lorenz number