First, the object that is easy to conduct electricity is a conductor. Such as: all kinds of metal, acid, alkali, salt solution, soil, human body and so on.
Second, the object that is not easy to conduct electricity is an insulator. Such as: glass, ceramics, rubber, plastics, etc.
Third, in addition, the conductive material between the conductor and the insulator is a semiconductor.
note:
1, there is no absolute boundary between conductor and insulator;
2. When conditions change, the conductor also becomes an insulator; Or the insulator becomes a conductor. conductor
Conductor: A conductor is an object that can conduct electricity. There are free electrons in metal conductors, and the reason for conducting electricity is free electrons. With the increase of temperature, the resistivity of semiconductor gradually decreases and its conductivity is greatly improved. The reason for conducting electricity is the hole and electron pair in the semiconductor.
Matter exists in various forms, such as solid, liquid, gas, plasma, etc.
We usually refer to materials with poor electrical and thermal conductivity, such as diamond, artificial crystal, amber, ceramics, rubber and so on, as insulators. Metals with good electrical and thermal conductivity, such as gold, silver, copper, iron, tin and aluminum, are called conductors. The material between conductor and insulator can be simply called semiconductor. In metal, some electrons can move freely inside the metal without being bound by the nucleus. This kind of electron is called a free electron. Metals conduct electricity through free electrons.
Compared with metals and insulators, the discovery of semiconductor materials is the latest. It was not until the 1930s, when the purification technology of materials was improved, that the existence of semiconductors was truly recognized by academic circles.
insulator
Substances that are not good at conducting current are called insulators, and insulators are also called dielectrics. Their resistivity is very high.
There are many kinds of insulators, such as plastics, rubber, glass and ceramics. Liquid, such as natural mineral oil, silicone oil, trichlorobiphenyl, etc. Air, carbon dioxide, sulfur hexafluoride and other gases.
Under the influence of some external conditions, such as heating and high voltage, the insulator will be "broken down" and converted into a conductor. Before decomposition, an insulator is not an absolutely nonconductive object. If a voltage is applied to an insulating material, a weak current will appear in the material.
There are usually only a few free electrons in insulating materials, and the charged particles involved in conduction before breakdown are mainly intrinsic ions and impurity particles dissociated by thermal motion. The electrical properties of insulators are reflected in the processes of conductance, polarization, loss and breakdown.