Copper

Copper has been hammered into tools for about ten thousand years, and alloying it with tin gave the Bronze Age its name; the element's own name traces back to Cyprus, the Roman Empire's main source. Its electrical conductivity is second only to silver, and unlike silver it is cheap enough to run through walls by the kilometre, so a typical electric car contains around 60–80 kg of it. Copper also shows the second great d-block anomaly, 3d¹⁰ 4s¹ rather than 3d⁹ 4s², a filled d shell being worth breaking the pattern for. The Statue of Liberty is 80 tonnes of copper about 2.4 mm thick — the thickness of two pennies — and its green is a copper carbonate and sulfate patina that protects the metal underneath. Copper surfaces are also self-disinfecting, killing bacteria left on them within hours.