The structure of an atom of an element is what makes it different from the atom of another element. The number of protons, neutrons, and electrons and the arrangement of the electrons in their orbits vary from element to element. In some elements, the outer electrons rotating around the nucleus are easily removed from their orbits. As stated earlier, elements that have atoms with this characteristic are called conductors. A conductor can transmit electricity or electrons.
Most metals are conductors, but not all metals conduct electricity equally well. The most common conductors are silver, copper, and aluminum. The high cost of silver prevents it from being used widely. Its use is largely limited to contacts in certain electrical switching devices such as contactors and relays. Copper, almost as good a conductor as silver, is usually used because it is less expensive.
Materials that do not easily give up or take on electrons are called insulators. An insulator retards the flow of electrons. Glass, rubber, and asbestos are examples of insulators. Thermoplastic is one of the best insulators used to cover wire today. How well an insulator prevents electron flow depends on the strength of the potential applied. If the potential is strong enough, the insulator will break down, causing electrons to flow through it.
There is no perfect insulator. All insulators will break down under certain conditions if the potential is high enough. Increasing the thickness of the insulation helps overcome this problem.
Conductors and insulators are important parts of electric circuits and electric systems. They are widely used in all electric components in the industry.