Which is a Good Conductor of Electricity?

Good and bad conductors define the flow of electricity concerning resistivity. Many metals are good conductors of electricity due to their free-flowing electrons, on the other hand, materials are bad conductors or insulators that insulate or resist to flow of the electrons freely. 

There are some of the best conductors include silver, copper, gold, and aluminum. Copper, in particular, is widely used in electrical wiring and electronics due to its excellent conductivity and affordability.

List of Electrical Conductor  Materials

The most commonly used electrical conductor materials are copper and aluminum, followed by silver and gold. The full list of Electrical Conductor  Materials is as below:

Table of Resistivity and Conductivity

Ranked from most to least conductive materials as per the periodic table reasonably good electrical conductors are:

Silver, Copper, Gold, Aluminum, Beryllium

Calcium, Magnesium, Rhodium, Sodium, Iridium

Tungsten, Molybdenum, Cobalt, Zinc, Nickel

Potassium, Cadmium, Ruthenium, Indium, Osmium

Lithium, Iron, Platinum, Palladium, Tin

Rubidium, Chromium, Strontium, Tantalum, Niobium

Gallium, Technetium, Thorium, Thallium, Rhenium

Why are Copper and Aluminium Conductors widely used in Power Transmission?

Copper and aluminum are widely used as conductors in power transmission for several reasons, most of which are as below:

Electrical Conductivity: Both copper and aluminum exhibit high electrical conductivity, meaning they allow electricity to flow through them with minimal resistance. Copper has a higher conductivity than aluminum, but aluminum is lighter, making it a more cost-effective option for long-distance transmission lines.

Cost: Aluminum is significantly cheaper than copper. Given that transmission lines cover vast distances, using aluminum conductors substantially reduces the overall cost of the materials needed for the infrastructure.

Weight: Aluminum is lighter than copper. This characteristic makes it easier and more cost-effective to transport and install over long distances. It also reduces the strain on towers and support structures.

Corrosion Resistance: Both copper and aluminum are naturally corrosion-resistant, ensuring the longevity and durability of the transmission lines, especially in various weather conditions.

Availability: Both metals are abundant and readily available, contributing to their widespread use in power transmission infrastructure.

Mechanical Properties: Aluminum possesses good mechanical properties suitable for overhead transmission lines. It can withstand the mechanical stress caused by wind, temperature changes, and its own weight when used in long spans.

Which Materials are the bad Conductors of Electricity?

No metal can be a bad conductor of electricity, in the sense that a bad conductor means less conductivity or an insulator. The material which is less conductor means a good insulator.  However, there are metals with relatively high resistivity among them, and some are used for resistors. If we consider metals with higher resistivity, we may list them accordingly. Lithium, Zinc, Nickel, and Tungsten in that order.

1. All dielectrics are bad conductors of electricity;
2. Demineralized(DM) water is a bad conductor of electricity;
3. Most polymers;
4. SF6 gas (used as dielectric for HV equipment).

Examples of Good Conductors and Bad Conductors

Examples of Good Conductors: are silver, copper, aluminum, gold, etc. In other words, these materials have very low resistivity.

Examples of Bad Conductors: are paper, Mica, glass, and teflon. These are the materials that offer very high resistance to the flow (or in the path) of electric Current.

Is it a Water Electrical Conductor or an Insulator?

Water is a terrible conductor of electricity.

Pure water is actually a poor conductor of electricity. However, water can become a conductor if it contains impurities or if it has dissolved ions present, which allow the flow of electrical current. Pure water itself, without any impurities, does not conduct electricity well.

To give you a comparison, pure deionized water has about 100,000 higher resistance than sea-water.