Conductors are materials that allow free flow of electrons from one particle to another. These are elements which have electric charges in the form of electrons that are comparatively free to move inside the material. When charge is transferred to such an element, it gets distributed across the entire surface of the object, which results in the movement of electrons in the object.
The charges transferred to a conductor distribute until the force of repulsion between electrons in areas of excess electrons is decreased to the minimum value. When such an object is brought in contact with another conductor, the charge gets transferred from the first conductor to the other until the overall repulsion due to charge is minimized. Some of the common example of conductors includes metals such as copper, gold, iron, etc. Graphite, human body and the earth are also good conductors of electricity.
Types of Conductors:
Metals: Most conducting materials used for practical applications are metals. For example, the wire around your house probably uses copper wires as conducting materials or their alloys. The electric plugs have metal in them, and the internal mechanism of you electric irons also use metals as their conducting material. This is because metals have lots of free electrons and promotes mobility. Some of the best metal conductors are Silver (Ag), Copper (Cu) and Gold (Au).
Non – Metals: There are some non – metals which are also very good conductor of electricity. For example, carbon in the form of graphite is a very good conductor of electricity. If you see the structure of graphite, only three of the four carbon atoms are used for bonding. This leaves one electron free for bonding. However, most non-metals are not good conductors of electricity.
Ionic Conductors: Conductors in their solution form are called ionic conductors. For example, salt water is an ionic solution and is a good conductor of electricity.
Semiconductors: Although semiconductors are not as good at conducting electricity as conductors, they still have their uses. Examples of semiconductors are Germanium (Ge) and Silicon (Si).