What material is best conductor of electricity?

Answer 1

In general, it is the metals that are the best conductors of electricity. Silver, copper and gold are the ones best at it, and in that order. Copper is common because it isn't too expensive. Silver tarnishes in air and it not broadly applied, though there is a growing use of it in solder. Gold is quite expensive, but because it is marvellously resistant to corrosion, it is used to plate connectors and such. There is, however, another "class" of conductors that are so much better, but there is a "catch" to using them.

At "room temperature" we see metals dominating as conductors, but in the world of cryogenics, they have to move over. Tin yttrium barium copper oxide for example, which is basically a ceramic, conducts at (a balmy) 86 K. That material is what is called a superconductor, and it will only work at a cryogenic temperature. It's super conductive properties disappear at any triple-digit temperature Kelvin. But when it's cooled below its "critical temperature" and inspected, its resistance has disappeared (it's zero!). Links are found below.