Group 11 element Parkes process. These metals, especially silver, have unusual properties that make them essential for industrial applications outside of their monetary or decorative value. They are all excellent conductors of electricity. The most conductive of all metals are silver, copper and gold in that order. Silver is also the most thermally conductive element, and the most light reflecting element. Silver also has the unusual property that the tarnish that forms on silver is still highly electrically conductive. Copper is used extensively in electrical wiring and circuitry. Gold contacts are sometimes found in precision equipment for their ability to remain corrosion-free. Silver
Ground (electricity) systems are often connected to ground to limit the voltage that can appear on distribution circuits. A distribution system insulated from ground may attain a high potential due to transient voltages caused by arcing, static electricity, or accidental contact with higher potential circuits. A ground connection of the system dissipates such potentials and limits the rise in voltage of the grounded system. In a mains electricity (AC power) wiring installation, the term "ground conductor" typically refers to three different conductors or conductor systems as listed below. "Equipment earthing conductors" provide an electrical connection between the physical ground (earth) and the