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 and it is measured in watts per square metre of surface area for a temperature gradient of 1 K per unit thickness of 1 m". Therefore, specific thermal conductivity is calculated as: where: formula_14 = temperature difference (K, or °C) = 1 K during measurement Absolute thermal conductivity, on the other hand, has units of formula_15 or formula_16, and can be expressed as where formula_18 = absolute thermal conductivity (W/K, or W/°C). Substituting formula_18 for formula_20 into the first equation yields the equation which converts from absolute thermal conductivity to specific thermal conductivity: Solving for formula_18, we get the equation