By Dianne Hermance | Updated Mar 24, 2022
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Copper is the metal most associated with pennies, but its influence extends far beyond coinage. Renowned for its exceptional electrical conductivity, copper is indispensable in modern infrastructure, renewable energy, and everyday electronics.
Copper (Cu, atomic number 29) is a bright red‑gold metal that has fascinated humanity since the Bronze Age, when it was alloyed with tin to create bronze. It is naturally ductile and malleable, allowing it to be drawn into fine wires or shaped into complex components without breaking. Copper’s high thermal conductivity (≈ 400 W m⁻¹ K⁻¹) and resistance to corrosion and oxidation make it ideal for electrical and thermal applications alike.
Common ore sources include chalcopyrite and bornite, from which copper is extracted via smelting and refined by electrolysis. Whether mined or recycled, copper retains its advantageous properties, ensuring a reliable supply for countless industries.
Electrical conductivity measures how readily a material carries electric current. Among non‑precious metals, copper tops the list, with a conductivity of 58 MS m⁻¹ (≈ 100 % IACS). Silver holds the absolute record but is too expensive for widespread use. Copper’s conductivity is benchmarked against the International Annealed Copper Standard (IACS), where pure copper scores 100 %.
Alloys alter conductivity: adding elements such as tin, magnesium, or zinc typically lowers it, while copper‑tellurium or copper‑sulfur alloys maintain high conductivity (64–98 % IACS). Trade‑offs between strength and conductivity are common; for example, brass (copper‑zinc) offers excellent castability but only 20–56 % IACS.
Copper’s ubiquity spans:
The metal’s recyclability and consistent performance guarantee that copper will remain a cornerstone of technology and sustainability for decades to come.
