Free electrons in a metal are known as conduction electrons. The flow of these free electrons is called an electrical current.
This can be expressed as the amount of charge flowing past a point in a given time.
Electric Current = a net flow of charge
The units of electric current is Coulumbs per second, called amperes (A).
Current flows in the opposite direction of the flow of electrons, in other words, it flows in the direction of the positive charge. Currents can exist in liquids and gases. If positive and negative charges were moving in the same direction, they would represent currents in opposite directions and the individual currents need to be subtracted to find the net current.
Example:
Electrolytes:
In an electrolytic mixture of KCl. The positive charges or (ions) move towards the negative electrode while the negative charges (Cl) move towards the positive electrode. In this case, the direction of the current would be the way the positive charges move.
