1. Common conductors?
1. Metal is the most common type of conductor, such as aluminum, iron, copper, silver, etc. Most metals are conductors. The valence electrons in the outermost layer of metal atoms can easily break away from the atomic nucleus and become free electrons, leaving behind positive ions (real atoms) forming a regular lattice.
The concentration of free electrons in metals is very large, so the electrical conductivity of metal conductors is usually greater than that of other conductive materials. The resistivity of metallic conductors generally decreases as temperature decreases. At extremely low temperatures, the resistivity of certain metals and alloys disappears and they become "superconductors."
2. The second type of common conductor is electrolyte solution, such as acid, alkali, and salt water solution. Its carriers are positive and negative ions. Experiments have found that although most pure liquids can also dissociate, the degree of dissociation is very small and therefore they are not conductors.
3. Ionized gas can also conduct electricity and is called a gas conductor. The carriers are electrons, positive and negative ions. Normally, gases are good insulators. If external factors are used, such as heating or irradiation with X-rays, gamma rays or ultraviolet rays, the gas molecules can be dissociated, so the ionized gas becomes a conductor.
4. Commonly used items in life, such as thumbtacks, steel rulers, aluminum bars, copper wires, kettles, paper clips, keys, pencil leads, etc. are all conductors. Graphite, water, human body, earth, wet wood, etc. are also common conductors.
2. Common insulators?
There are many types of insulators: the first type is solid, such as plastic, rubber, glass, ceramics, amber, etc.; the second type is liquid, such as Various natural mineral oils, silicone oils, trichlorobiphenyl, etc.; The third category is gases, such as air, carbon dioxide, sulfur hexafluoride, etc.
In daily life, glass rods, glasses, plastic rulers, rubber, wooden blocks, sharp knife handles, cooking oil, etc. are all common insulators.
Extended information
The relationship between conductors and insulators?
Insulators and conductors are not absolute, and there is no insurmountable gap between them. The difference between the two is mainly the number of internal charges that can move freely, but it is also related to external conditions (such as voltage, temperature, etc.). Objects that are insulating at room temperature will transform into conductors when the temperature rises to a considerable extent due to the increase in the number of freely mobile charges.
Under the influence of certain external conditions (such as heating, high voltage, etc.), insulators will be "broken down" and transformed into conductors. An insulator is not an absolutely non-conductive object until it is broken down.
If a voltage is applied across an insulating material, a weak current will appear in the material. There are usually only trace amounts of free electrons in insulating materials, and the charged particles that participate in conduction before breakdown are mainly intrinsic ions and impurity ions.
Intrinsic ions are ions dissociated due to thermal motion, and impurity ions are produced due to the dissociation of impurities. The main electrical properties of insulators or dielectrics are reflected in processes such as conductance, polarization, loss and breakdown.
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