It is obvious to the observant eye that many of the contraptions, gadgets and gizmos that make modern life such a privilege require some form of power to operate. This power runs through wires behind walls, beneath the ground and is accessed via enigmatic wall sockets to which all manner of devices are collected.
But why metal? All this wiring, connecting and powering seems to be focused on the way metals can convey this energy from place to place. So, what is it about metals that make them so excited by electrical currents— or better said what makes them good “conductors” of electricity?
Do all metals conduct electricity equally? Do any metals not conduct electricity? All these answers and more coming up in the following paragraphs.
Metals Conduct Electricity
The reason metals make such good conductors of electricity is that the atom forces that hold the outermost electrons in place are very weak. This means these electrons are able to move or flow easily into each other. The flow of electrons through materials is what makes electrical currents that can power our modern lifestyles.
The atomic configuration of a material decides what types of bonds will be made of their atoms. Remember that atoms are those tiny little specks of matter each with different amounts of electrons; those with large amounts of electrons are relatively stable.
On the other hand, atoms with fewer amounts of electrons have a “loose grip” on their electrons and can pass them on and receive others easily. In certain metals that make better conductors, like silver and copper, for example, the flow of electrons around their metallic atoms is very fluid.
This means those electrons are free to move with the flow of electricity, the easier the electrons flow the better the conductor.
The electrons in a metal to which an electrical field has been applied will begin to move quickly from place to place. Electrons, having the same charge, will repel each other. So when one free moving electron jumps off its atom into another atom, it will dislodge any electron it finds forcing it into the next atom where the process will continue. When this process is moving in a specific direction it is called a “current”. When this current is arranged in a loop, you have a “circuit”.
Which Metals are the Best Conductors of Electricity?
Silver, Aluminium, and Copper are the best metallic conductors of electricity. Although you should never pull the insulation off the power cables, as this is a risky activity, you would the familiar reddish color of a copper penny below. Aluminum is also used extensively as a conductor and silver are considered too expensive for common use.
Silver— Silver is the attractive whitish metal whose brilliance has been highly valued since ancient times. It is the best conductor of heat and electricity of all the metals and also offers the lowest contact resistance — also pretty expensive.
Copper — Copper is actually the second best on the list. Copper has been used since ancient times as it is highly practical and can be drawn into thin wires for ornate and intricate ornamental work. The demands for copper are extremely high, especially in modern industrialized countries.
Aluminum— is a soft lightweight metal that is also extremely strong. It conducts electricity with 61% efficiency when compared to the conductivity of copper. Although it is used often in electronics it is not often used in domestic wiring.
Are there any metals that do not conduct electricity?
Although all metals will conduct electricity to some degree — this is because, as mentioned, all metal atoms have electrons that can move about from atom to atom with different levels of ease. This means that some metals are more conducive to this flow than others.
We have already established that the best conductors are silver, copper, and aluminium. The worst conductors are those which have been treated with carbon to make steel. Stainless steel, carbonized steel, and pure lead may be the worst conductors, but don’t think that will spare you from a shock.
To actually prevent the flow of electricity you’ll need an insulator. Simply, a material that lacks the free-flowing electrons you will find in a metal.