Electric conductivity is the movement of electrically charged particles. All metals conduct electricity to a certain extent, but certain metals are more highly conductive. The most highly conductive metals are silver, copper, and gold.
Copper, for example, is highly conductive and commonly used in metal wiring. Brass, on the other hand, contains copper but other materials in its makeup reduce conductivity. Pure silver is the most conductive of all metals.
This list shows the conductive order of some commonly used metals and alloys, based on equal sizes.
- Pure silver
- Pure copper
- Pure gold
- Stainless steel
Why is silver at the top of the list? The presence of valence electrons determines a metal’s conductivity. Valence electrons are “free electrons” that allow metals to conduct electric current. Free electrons move through metal like billiard balls, transferring energy as they knock into each other. Silver and copper are metals with single, free-moving valence electrons. The valance moves throughout the metal with little resistance, making these metals more conductive.
Semi-conductor metals have multiple valence electrons, which reduces the repelling reaction. Think of that 8-ball again: when it hits one ball, it knocks it farther than if it gently bumps into multiple balls. Semi-conductors, however, can become more effective electrical conductors when heated or combined with other elements. The resistance of semiconductors depends on the presence of impurities in the metal. In addition to impurities, other factors that can affect how a metal conducts electricity include frequency, eletctromagnetic fields, and temperature.
Silver has the highest conductivity of all metals, but it also has a hefty price tag and it can tarnish, rendering the surface less conductive. Gold is more corrosion resistant. Copper’s high conductivity and affordability make it a more appealing choice.