The most electrically conductive metal in the world
The value of metals is directly determined by theirchemical and physical properties. In the case of such an indicator as electrical conductivity, this connection is not so straightforward. The most conductive metal, if measured at room temperature (+20 ° C), is silver.
The physical meaning of conductivity
The use of metallic conductors hasa long-standing history. Scientists and engineers working in the fields of science and technology using electricity have long been determined with materials for wires, terminals, contacts, printed circuit boards, etc. The physical quantity called electrical conductivity helps to determine the most electrically conductive metal in the world.
The concept of conductivity back to electricalresistance. The quantitative expression of conductivity is related to the unit of resistance, which in the international system of units (SI) is measured in Ohms. The unit of electrical conductivity in the SI-Siemens system. The Russian designation of this unit is Sm, the international one is S. The electrical conductivity of 1 cm is possessed by a section of an electrical network with a resistance of 1 ohm.
Conductivity
Measure the ability of a substance to conduct an electric currentis called the electrical conductivity. The highest similar indicator is the most electrically conductive metal. This characteristic can be determined for any substance or medium instrumentally and has a numerical expression. The specific electrical conductivity of a cylindrical conductor of a single length and a unit cross-sectional area is related to the resistivity of a given conductor.
The systemic unit of conductivity isSiemens per meter - S / m. To find out which of the metals is the most electrically conductive metal in the world, it is enough to compare their conductivity, determined experimentally. It is possible to determine the specific resistance by means of a special device - a microhmmeter. These characteristics are inverse.
Conductivity of metals
The concept of electric current itselfdirected flux of charged particles seems more harmonious for substances based on crystal lattices peculiar to metals. Carriers of charges at occurrence of an electric current in metals are free electrons, instead of ions, as it happens in liquid media. It has been established experimentally that when a current flows in metals, there is no transfer of particles of matter between the conductors.
Metallic substances differ from others morefree connections at the atomic level. The internal arrangement of metals is distinguished by the presence of a large number of "single" electrons. which at the slightest influence of electromagnetic forces form a directed flow. Therefore, it is not for nothing that metals are the best conductors of electric current, and it is these molecular interactions that distinguish the most electrically conductive metal. On the features of the structure of the crystal lattice of metals, one more specific property is based - a high thermal conductivity.
Top best conductors - metals
4, metals having practical significance for their use as electrical conductors are distributed in the following order with respect to the value of the conductivity measured in cm / m:
- Silver - 62 500 000.
- Copper - 59 500 000.
- Gold - 45 500 000.
- Aluminum - 38 million.
It can be seen that the most electrically conductive metal is silver. But like gold, it is used to organize an electrical network only in special specific cases. The reason is high cost.
But copper and aluminum - the most commonoption for electrical appliances and cable products due to low resistance to electric current and price availability. Other metals are rarely used as conductors.
Factors affecting the conductivity of metals
Even the most electrically conductive metal reduces itsconductivity, if it contains other additives and impurities. In alloys, the structure of the crystal lattice is different than that of "pure" metals. It is distinguished by a violation in symmetry, cracks and other defects. The conductivity decreases with increasing ambient temperature.
The increased resistance inherent in alloys,finds application in heating elements. It is not accidental that for working elements of electric furnaces, heaters are used by Nichrome, Fechral and other alloys.
The most electrically conductive metal is precioussilver, more used by jewelers, for minting coins, etc. But even in engineering and instrument making, its special chemical and physical properties find wide application. For example, besides using it in knots and aggregates with reduced resistance, silver spraying protects contact groups from oxidation. The unique properties of silver and its alloys often make its use justified, despite the high cost.
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