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The best conductor of electricity among the elements is silver. At room temperature it conducts slightly better than copper and noticeably better than gold. Yet almost every wire in your home is copper, and the connectors on your electronics are often gold-plated. The reasons say a lot about how materials are chosen in practice.
The ranking
Approximate electrical conductivity of the best conducting elements at 20 °C, relative to copper:
| Element | Conductivity relative to copper |
|---|---|
| Silver | ~106% |
| Copper | 100% |
| Gold | ~70% |
| Aluminium | ~61% |
| Calcium | ~50% |
| Tungsten | ~31% |
| Zinc | ~29% |
| Iron | ~17% |
(Engineers often use the “% IACS” scale, where 100% is a standard annealed copper, so very pure copper can score slightly above 100.)
Why metals conduct at all
In a metal, the outer electrons aren’t tied to individual atoms. They form a “sea” of delocalized electrons that moves through the lattice of metal ions — see metallic bonding. When a voltage is applied, those electrons drift in one direction, and that drift is an electric current.
What limits conductivity is how often the moving electrons are scattered — by vibrating atoms, impurities and defects in the crystal. The fewer the collisions, the better the conductor.
Why silver, copper and gold are the best
Silver, copper and gold sit together in group 11 of the periodic table. Each has a single s electron outside a completely filled d subshell ([Kr] 4d¹⁰ 5s¹ for silver, [Ar] 3d¹⁰ 4s¹ for copper). That lone electron is very mobile and scatters relatively little, which makes all three excellent conductors. Silver’s combination of electronic structure and crystal lattice gives it the edge.
Why we use copper instead of silver
- Cost. Silver is dramatically more expensive than copper. A 6% improvement isn’t worth it for household wiring.
- Abundance. Copper is much more plentiful.
- Practical properties. Copper is strong, ductile, easy to solder and resists corrosion well enough.
- Tarnish. Silver tarnishes (forming silver sulfide), which can affect contacts.
Silver is used where the last bit of performance matters: some high-frequency cables, silver-plated connectors, and conductive inks and pastes in electronics and solar cells.
Why gold-plated connectors?
Gold conducts less well than copper, but it has one unbeatable property: it doesn’t corrode or tarnish. A thin gold layer keeps a connector’s surface clean and reliable for years, so small currents pass consistently. That’s why you find gold on circuit board edge connectors, SIM card contacts and high-quality audio plugs.
Why power lines use aluminium
Aluminium conducts only about 61% as well as copper by volume, but it’s about a third of the density. Per kilogram, aluminium is roughly twice as good a conductor as copper. For long overhead transmission lines, where weight and cost matter enormously, aluminium (usually with a steel core for strength) is the standard choice.
Temperature matters
For metals, conductivity falls as temperature rises, because the vibrating atoms scatter electrons more. Cool certain materials enough and something remarkable happens: their resistance drops to exactly zero. That’s superconductivity, used in MRI scanners and particle accelerators. Curiously, the best ordinary conductors — silver, copper and gold — don’t become superconductors at all, even near absolute zero.
Non-metal conductors
Graphite (a form of carbon) conducts well along its layers, which is why it’s used for electrodes. Semiconductors like silicon and germanium conduct poorly when pure but can be tuned precisely by adding tiny amounts of other elements — the basis of all modern electronics.
Quick answers
What is the best conductor of electricity? Silver.
What is the best conductor of heat? Among elements, also silver among metals — but diamond conducts heat even better, despite being an electrical insulator.
Is gold a better conductor than copper? No. Copper conducts better; gold is used because it doesn’t corrode.
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