Silver metal. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm. At wavelengths shorter than 450 nm, silver's reflectivity is inferior to that of aluminium and drops to zero near 310 nm. Very high electrical and thermal conductivity is common to the elements in group 11, because their single s electron is free and does not interact with the filled d subshell, as such interactions (which occur in the preceding transition metals) lower electron mobility. The electrical conductivity of silver is the greatest of all metals, greater even than copper, but it is not widely
Conductivity near the percolation threshold of the perfect insulator and just finite metallic clusters. The exponent t is one of the two critical exponents for electrical percolation. In the other well-known case of a superconductor-conductor mixture we have formula_18. This case is useful for the description below the percolation threshold: formula_19 for formula_20 Now, above the percolation threshold the conductivity becomes infinite, because of the infinite superconducting clusters. And also we get the second critical exponent s for the electrical percolation. In the region around the percolation threshold, the conductivity assumes a scaling form: formula_21 with formula_22 and formula_23 At the percolation threshold, the conductivity