What is a common characteristic of good electrical conductors?

A common characteristic of good electrical conductors is high electrical conductivity, which refers to a material's ability to allow the flow of electric current. Materials with high electrical conductivity, such as copper and aluminum, have a large number of free electrons that can move easily through the lattice structure of the material when an electric field is applied. This property makes them highly efficient for transmitting electric current in wires and electrical components.

In contrast to the qualities associated with good conductors, low ductility would imply that a material is brittle and cannot be easily shaped, which is not desirable for conductors that may need to be formed into wires. High thermal resistance indicates a material's ability to resist the flow of heat, which is also not beneficial for conductors, as good conductors are typically efficient at dissipating heat generated by electric current. Low density alone does not encompass the essential property needed for conductivity, as a material can be lightweight yet still poor in conducting electricity.