Metals are good conductors of electric current for which of the following reasons? They possess high concentrations of protonsThey possess low concentrations of protonsThey possess high concentrations of free electronsThey possess low concentrations of free electrons

The correct answer is: They possess high concentrations of free electrons

The main characteristic of good conductors such as metals is the presence of movable electrically charged particles, or electrons. So, when an electric current is applied to a metal, the electrons will move and allow electricity to pass through them. Materials opposite of metals, with low electron mobility are not good conductors, instead they are called insulators.