CONDUCTORS, INSULATORS AND SEMICONDUCTORS

 

Electric conductivity 

Electric conductivity is the ability of a material to allow changes to flow through them.

Electric conductivity of all materials around as is not the same, conductivity differ because of their differences in chemical structure. Based on this differences in electric conductivity, materials can be classified as conductors, insulators and semiconductors. 

Conductors

 Materials that allow electric charges to pass through them easily are known as conductors. Conducting materials have  free electrons ( electrons have negative charge) in their atoms, which is responsible for conductivity.

Examples:- most of metals like iron, copper, aluminium etc are conductors 

Insulators 

 Materials that do not allow electric charges to flow through them are known as insulators. An insulating material does not have free electrons in their atom, so charges cannot flow through them.

Examples:- wood, plastic, rubber etc

Semiconductors 

Materials that shows properties of both conductors and insulators are generally known as semiconductors. In normal conditions semiconductors act as insulators, but increasing temperature and doping ( adding some impurities) allow semiconductors act like conductors.

Examples :- silicon, germanium etc