Used in electronics for reliable, corrosion-resistant connectors and contacts due to excellent conductivity and stability. Common in aerospace and high-end devices like smartphones and computers. Widely applied in dentistry for crowns and bridges because of biocompatibility and resistance to tarnish. Essential in jewelry and decorative items for its luster, durability, and ability to be finely detailed. Used in medicine, particularly in treatment of rheumatoid arthritis with gold salts. Applied in nanotechnology; gold nanoparticles are used in diagnostics, drug delivery, and cancer therapy. Used as a catalyst in chemical reactions, especially in air purification and carbon monoxide oxidation. Popular in investment and finance as bullion and coins due to long-term value retention. Used in aerospace and satellite technology as a thin coating to reflect infrared radiation and protect against heat.