Au

Gold (Au) is a noble metal prized for its exceptional corrosion resistance, electrical conductivity, and biocompatibility. It is widely used in electronics, jewelry, dentistry, and medical devices where reliability and inertness are critical, and in aerospace and defense applications where extreme environmental stability is required. Engineers select gold primarily when corrosion immunity and long-term performance justify its high cost, or when its unique combination of workability and chemical stability is irreplaceable—such as in bonding wires for microelectronics or implantable medical components.