Silver Silver Silver is a chemical element with symbol Ag (from the Latin "", derived from the Proto-Indo-European "h₂erǵ": "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining. Silver has long been valued as a precious metal. Silver
Thermal conductivity Time variation due to phonon decay is described with a relaxation time ("τ") approximation which states that the more the phonon number deviates from its equilibrium value, the more its time variation increases. At steady state conditions and local thermal equilibrium are assumed we get the following equation Using the relaxation time approximation for the Boltzmann equation and assuming steady-state conditions, the phonon thermal conductivity "λ" can be determined. The temperature dependence for "λ" originates from the variety of processes, whose significance for "λ" depends on the temperature range of interest. Mean free path is one factor that determines the