Here's why:
* Conductors are materials that allow the easy flow of electric charge. This is because they have loosely bound electrons in their outer shell, which are easily freed to move.
* Electric current is defined as the flow of electric charge.
* When a voltage is applied across a conductor, it creates an electric field that pushes these free electrons in a specific direction. This directed movement of electrons constitutes the electric current.
While protons also carry electric charge, they are much heavier and tightly bound within the atom's nucleus. This makes them essentially immobile in conductors, and therefore not involved in the flow of current.
