In the field of electricity, there are those materials that do allow current to pass through them and there are those materials that don’t allow electric current to flow through them. Those that allow electric current to pass through them are referred to as conductors while those that don’t allow electric current to pass through them are referred to as insulators.
Electrical conductors are those materials that allow current to flow through them. They have free electrons that could move.
Materials like metals are known to conduct electricity. The main reason behind this is because they have a metallic bonding structure, which results to a positive ion engulfed in a sea of electrons. An atom of a metal gives out all its outer shell electrons to the electron pool. This makes the metals to have very many free electrons that can conduct electricity. And this is the reason as to why they are very good conductors of electricity.
Conduction of electricity can also be viewed as a result of the hole flow. When an atom in the lattice structure donates an electron, the atom is left positively charged since the number of electrons become lesser than the number of the protons in the nucleus of the atom. The unfilled empty place that the electrons leave in the outer most energy level of the atom is referred to as a hole. An electron from a neighboring atom can be taken up so as to fill the hole. When the hole is filled the atom from which the electron to fill the hole came from is left with a hole. Therefore as the electrons move forward there are holes that seem to move backwards. When the shift of this holes continue in a succession manner, there is said to be an electric flow.
There are also ionic solutions that are conductive in nature. However the charge carriers in the ionic solutions are the ions which can either be negative or positive.
Electrical insulators are materials that don’t allow electric charges to flow through them. The main cause of their insulating property is because they do not have any free charges.
Examples of insulators are distilled water, paper, plastic, mica and ceramics.
The main differences between electric conductors and electric insulators
1. The electrical conductors have very little electrical resistance, while electrical insulators have very high to infinite electrical resistance.
2. Electrical conductors have free charges, while insulators have no free charges.
3. Electrical conductors let electric current to flow through them, while electric insulators do not allow electric current to flow through them.
The above knowledge and content are usually covered during our Physics tuition classes for secondary school students. Eventually, you will venture into semiconductors at college level. Tune in to find out more!