Let’s go back to the periodic table to explain which metals best conduct electricity. The number of valence electrons in an atom is what makes a material able to conduct electricity. The outer shell of the atom is the valence. In most cases, conductors have one or two (sometimes three) valence electrons.
Metals that have ONE valence electron are copper, gold, platinum, and silver. Iron has two valence electrons. Even though Aluminum has three valence electrons, it is an excellent conductor as well. A semiconductor is a material that has four valence electrons.
Metallic bonding causes metals to conduct electricity. In a metallic bond, atoms of the metal are surrounded by a constantly moving “sea of electrons”. This moving sea of electrons enables the metal to conduct electricity and move freely among the ions.
Most metals conduct electricity to a certain extent. Some metals are more highly conductive than others. Copper, silver, aluminum, gold, steel, and brass are common conductors of electricity. The most highly conductive metals are silver, copper, and gold.
Which Metal is the Best Conductor of Electricity?
This list of electric conductivity includes alloys as well as pure elements. Because the size and shape of a substance affect its conductivity, the list assumes all samples are the same size. Here are the basic types of metals and some common alloys in order of best to worst conductors of electricity:
From best to worst (equally sized):
- Stainless Steel
“Silver is the best conductor of electricity because it contains a higher number of movable atoms (free electrons). For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity. However, silver is more expensive than other materials and is not normally used unless it is required for specialized equipment like satellites or circuit boards”, explains Sciencing.com.
“Copper is less conductive than silver but is cheaper and commonly used as an effective conductor in household appliances. Most wires are copper-plated and electromagnet cores are normally wrapped with copper wire. Copper is also easy to solder and wrap into wires, so it is often used when a large amount of conductive material is required’, reports Sciencing.com
While gold is a good electric conductor and doesn’t tarnish when exposed to the air, it is too expensive for common use. Individual properties make it ideal for specific purposes.
Aluminum can conduct electricity but it does not conduct electricity as well as copper. Aluminum forms an electrically resistant oxide surface in electrical connections, which can cause the connection to overheat. High-voltage transmission lines which are encased in steel for additional protection use aluminum.
ScienceViews.com explains that “Zinc is a blue-gray, metallic element, with the atomic number 30. At room temperature, zinc is brittle, but it becomes malleable at 100 C. Malleable means it can be bent and shaped without breaking. Zinc is a moderately good conductor of electricity”.
Most metals conduct electricity. Nickel is an element with high electrical conductivity.
Brass is a tensile metal used for smaller machines because it is easy to bend and mold into different parts. Its benefits over steel are that it is slightly more conductive, cheaper to purchase, less corrosive than steel, and still retains value after use. Brass is an alloy.
Bronze is an electrically conductive alloy, rather than an element.
Iron has metallic bonds which is where the electrons are free to move around more than one atom. This is called delocalization. Because of this, iron is a good conductor.
Platinum is an element with high electrical conductivity and is more ductile than gold, silver, or copper. It is less malleable than gold. The metal has excellent resistance to corrosion, is stable at high temperatures, and has stable electrical properties.
Steel is a conductor and an alloy of iron. Steel is typically used to encase other conductors because it is an inflexible and highly corrosive metal when exposed to air.
“Although lead compounds can be good insulators, pure lead is a metal that conducts electricity, making it a poor insulator. Lead’s resistivity is 22 billionths of a meter. It sees use in electrical contacts because, being a relatively soft metal, it deforms easily when tightened and makes a solid connection. For example, the connectors for car batteries are typically made of lead. A car’s starter motor draws over 100 amperes of current briefly, requiring a robust connection to the battery” explains Sciencing.com.
Stainless Steel Conductivity
Stainless steel is a relatively good conductor of electricity, as are all metals.
Factors That Affect Electrical Conductivity
Certain factors can affect how well a material conducts electricity. ThoughtCo explains these factors here:
- Temperature: Changing the temperature of silver or any other conductor alters its conductivity. In general, increasing the temperature causes thermal excitation of the atoms and decreases conductivity while increasing resistivity. The relationship is linear, but it breaks down at low temperatures.
- Impurities: Adding an impurity to a conductor decreases its conductivity. For example, sterling silver is not as good of a conductor as pure silver. Oxidized silver is not as good a conductor as untarnished silver. Impurities hinder electron flow.
- Crystal structure and phases: If there are different phases of a material, conductivity will slow slightly at the interface and may be different from one structure to another. The way a material has been processed can affect how well it conducts electricity.
- Electromagnetic fields: Conductors generate their own electromagnetic fields when electricity runs through them, with the magnetic field perpendicular to the electric field. External electromagnetic fields can produce magnetoresistance, which can slow the flow of current.
- Frequency: The number of oscillation cycles an alternating electrical current completes per second is its frequency in hertz. Above a certain level, a high frequency can cause current to flow around a conductor rather than through it (skin effect). Since there is no oscillation and hence no frequency, the skin effect does not occur with direct current.
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