When electricity flows through a metal, it means that the “free” electrons, those that are allowed to move, start to move. They are electrically charged, and this electron movement creates the electric current. The electric current is called “I” and appears when there is an electric potential – called “V” – according to Ohm’s law:
V = R I
“R” stands for the electric resistance. The higher the electric potential difference, the more current you get. Conversely, if the electric resistance is high, the current will be low. In other words, a metal with a weak resistance is a better conductor. If you have an electric resistance, it means that the electrons are slowed in the metal.
In an electric network, the battery creates an electric current by setting the electrons in motion. These electrons collide with the flaws of the electric conductor. They release energy to the material, which starts heating, causing them to slow down. This is the origin of electric resistance. Of course, all the free electrons in the network start moving at the same time, which cannot be seen in the animation for clarity reasons.
Measure of the electrical resistance in a metal.