Conductivity can be divided into two categories: ____ conductivity.

Conductance is the reciprocal of ____.

The SI unit for conductance is ____.

Some materials allow free flow of electric charge within them; these materials are called ____.

The ____ has often been visualized as a sea of electrons flowing over and past a rigid lattice of metal cations.

Due to ____, electrons are free to move around in the metal, conducting electrical charges.