1. Conductor is a material that allows charge carriers (usually electrons) to move with ease among atoms. Examples are metals, electrolytes, and ionized gases. Substances vary widely in their suitability as conductors; the conductivity of commercial copper, for example, is almost twice that of aluminum.
2. The term conductor is applied to any material that will support a generous flow of charge when a voltage source of limited magnitude is applied across its terminals. Good conductors have low resistance so electrons flow through them with ease. The atomic structure of good conductors usually includes only one electron in their outer shell.
Best element conductors include:
Copper (Cu), silver (Ag), gold (Au), aluminum (Al), and nickel (Ni)
Alloys are also good conductors:
Brass and steel
Good conductors can also be liquid: