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
Thermal conductivity given thickness of a material, that particular sample's "thermal resistance" and the reciprocal property, "thermal conductance", can be calculated. Unfortunately, there are differing definitions for these terms. Thermal conductivity, "k", often depends on temperature. Therefore, the definitions listed below make sense when the thermal conductivity is temperature independent. Otherwise a representative mean value has to be considered; for more, see the Equations section below. For general scientific use, "thermal conductance" is the quantity of heat that passes in unit time through a plate of "particular area and thickness" when its opposite faces differ in temperature by one kelvin. For a