The metals that conduct electricity the best are silver, copper and aluminum. Both copper and aluminum are used extensively in electrical wiring. Silver, though it conducts electricity better than either of the other two, is too expensive for common usage.
Known since antiquity, silver is a brilliant metal whose chemical symbol is Ag, after argentum. It not only conducts electricity better than other metals but also conducts heat better. It also has the lowest contact resistance.
Copper is the second best conductor of electricity. Also known since ancient times, copper is a bright reddish metal that can also be drawn into thin wires. It's been used to conduct electricity since the early part of the 19th century.
Aluminum, a strong, soft but lightweight metal, is also an excellent conductor of electricity. It conducts electricity 61 percent as well as copper even though it's less dense. However, aluminum wiring isn't used much in residential electrical systems because of problems that had little to do with the qualities of the metal, but how it was installed. Much aluminum wiring was installed after World War II, when copper wire was scarce. The demand resulted in substandard installation, which resulted in circuit failures and fires.