* Metals have free electrons: Unlike other materials, metals have electrons in their outer shells that are loosely bound to the atoms. These electrons are free to move throughout the metal's structure.
* Electric field creates motion: When a voltage is applied across a metal wire, it creates an electric field. This field exerts a force on the free electrons, causing them to drift in a specific direction.
* Drift velocity: The electrons don't move in a straight line at high speeds. Instead, they constantly collide with atoms and other electrons, resulting in a slow, directed drift. This drift velocity is much slower than the speed of individual electrons, but it's enough to constitute a current.
In summary, an electric current in a metal is the flow of free electrons driven by an electric field.
