Used in electronics for reliable conductive connections in connectors, switches, and printed circuit boards due to excellent corrosion resistance and conductivity. Common in aerospace and high-reliability devices where performance under stress is critical. Widely applied in dentistry for crowns, bridges, and fillings because of biocompatibility and resistance to tarnish. Essential in nanotechnology, especially gold nanoparticles, for medical diagnostics, drug delivery, and cancer treatment through photothermal therapy. Used in jewelry and decorative items for aesthetic appeal and long-term luster. Plating gold on surfaces improves reflectivity and durability in optical instruments and infrared shielding. Important in catalysis, especially in carbon monoxide oxidation and organic synthesis, where supported gold nanoparticles show high activity at low temperatures. Used in central banking and investment as bullion and coins due to intrinsic value and stability.