HOW IS ELECTRIC CURRENT FLOWING THROUGH COPPER WIRE
It is well known fact that copper is good electrical conductor and that it is used in everyday life for that exact purpose. But, however, how is current flowing through copper wire?
Before we answer that question, lets remind ourselves some things that we have learned until now.
Valence electrons – those are those electrons that are in the last orbital of an atom. By using little force, these electrons can be ‘kicked out’ from an atom and then those electrons will search around for other atoms or molecules which will be attracted to it.
There are two types of charges; positive and negative. They are attracted to each other, while the charges of the same type are repelling each other.
Now, for an example, lets take an atom of copper which has one valence electron:
This is a display of one atom of copper. Now lets imagine a copper wire, it is made of bunch of these atoms. Because of easier display, we will have to simplify the look of copper wire and atoms. Chemical symbol for copper is: Cu. So this is how we are going to mark their nucleus and we are going to draw only this last, forth one orbital, where is valence electron. So, these three we will skip. Because of easier display and demonstration.
Copper wire made of atoms of copper:
Now lets say that we are able to kick out this valence electron from atom ‘A’. What that electron would do? It would search for new atom, in this case, that is atom ‘B’. What happens now?
Now, here we have two electrons. Logically, both are negatively charged, and lets remind ourselves what is happening when we have two negative charges.? They are repelling each other. And now this electron that came from atom ‘A’ to atom ‘B’, will kick out its valence electron, and then that electron will go to atom ‘C’.
And again the same story. In atom ‘C’ we have two electrons. This new one will kick out this old one and that one will go to the next atom, atom ‘D’.
Now we can more easily visualize how it is happening. This is the reason why we are making electrical circuits, so that current can flow back.