conductors of electricity

Why Are Metals Good Conductors of Electricity?

In 1752 the American inventor Benjamin Franklin created the lightning rod. He discovered the conduction of electricity while flying a kite with a metal key. During a storm, he noted that the electricity seemed drawn towards the key.

This led him to conclude that the power of the electrical storm traveled to metal. This was one of the first experiments proving that metal conducts electricity.

Why are metals such good conductors of electricity, though? Why are certain metals chosen over others? What causes this to happen?

Today we hope to help you understand all of the intricacies of electric conduction!

What Is a Conductor of Electricity?

Electrical conductors are materials that transfer electricity through them. These materials have a favorable molecular structure. When these structures exist, it permits the free movement of electrical charge.

This means the material does not impede the flow of the electrical currents. Some materials have a more solid structure. Others have more volatile molecular structures and are less inhibitive to electrical flows.

Materials that are good at conducting electricity are known as a conductor. Materials that consume electricity and do not permit it to travel are referred to as insulators.

Of course, the study of electricity, electrical circuits and systems is not trivial. This article will serve as a good basic foundation of why certain metals are better conductors of electricity than others.

What Makes a Good Conductor?

Any material that exhibits highly conductive properties and has a molecular structure that is favorable for free electron flow will make for a good conductor.

Metals conduct electricity very well, but some metals are better than others. Metals have a very strong bond between atoms, which prevents them from melting during heating. Metals also has many free moving electrons throughout their structure.

This is what makes metal such a unique substance when it comes to electricity conduction. The strong structure permits it to remain solid throughout the electrical power surge. But, it is malleable enough to permit the electrons to carry the power through it.

What Metals are Good Conductors?

Image showing copper wire one of the most highly conductive metals.

Copper, a widely used conductor in electrical wiring, conducts electricity very efficiently. It stands out for its adaptable and malleable nature. The abundance of free electrons in copper, along with its strong atomic bond preventing melting during heating, contributes to its exceptional conductivity.

Gold, although not as conductive as copper, possesses a high electrical conductivity, meaning it allows the flow of electric current with minimal resistance. It also exhibits significant tarnish resistance, making it valuable for specific applications where corrosion resistance is crucial. However gold is expensive, which limits its applications.

Silver takes the lead as the best conductor among metals, surpassing both copper and gold in conductivity. However, its high tarnishing rate limits its widespread use in electronics.

Some other highly conductive metals that are widely used include:

  • Aluminum
  • Brass
  • Bronze
  • Nickel
  • Tungsten
  • Zinc

In each case, the choice of these metals depends on a combination of factors, including conductivity, cost, corrosion resistance, and specific application requirements. Engineers and manufacturers carefully select materials based on the unique properties needed for a particular electrical component or system.

Why are Pure Metals Better Conductors?

In a pure metal, such as copper or silver, the atoms are arranged in a regular lattice structure. Each metal atom contributes one or more electrons to a “sea” of electrons that move freely throughout the metal lattice.

These free electrons are not bound to any specific atom and are able to move easily through the metal structure in response to an applied electric field.

The absence of impurities or alloying elements in pure metals also contributes to their superior conductivity. Impurities or alloying can introduce irregularities in the crystal lattice, disrupting the smooth movement of electrons.

In contrast, the regular arrangement of atoms in pure metals allows for a more unhindered flow of electrons. These characteristics make pure metals the material of choice for applications where high conductivity is essential, such as in electrical wiring, power transmission lines, and various electronic components.

While alloys may offer other desirable properties like increased strength or corrosion resistance, pure metals remain unparalleled when it comes to electrical conductivity.

What Makes a Poor Conductor of Electricity?

If metals conduct electricity efficiently, what materials don’t? Wood, stone, rubber, and glass are good insulators.

Insulators possess solid structures that resist the flow of free moving electrons. This distinction is crucial in electrical applications, where the choice of materials, and the material’s ability, dictates the efficiency and safety of a system.

Whether it’s the copper wiring in your home carrying electrical currents or the rubber insulation safeguarding those wires, the interplay between conductors and insulators forms the backbone of modern electrical engineering, ensuring the reliable and secure transmission of electrical power.

Different Metallic Bonds

As discussed above, the structure of the metal is what makes them such good electrical conductors. Metal has a way of both being a solid structure while permitting electrons to pass through.

Metals have different forms of metallic bonds. This impacts how the electricity flows through the metal. As a result, some metals are better than others at conducting electricity.

We will explore some of the best metal conductors in the next major section. First, we will explore various metallic structures and how they bind together. This heavily impacts the transfer of electricity between substances.

What is an Ionic Bond?

An ionic bond refers to how electricity travels from metals to non-metals. But, more specifically, it refers to the charge between differently charged atoms.

Some are negatively charged, and some are positively charged. The bonding of this element creates a new substance. Some examples of ionic bonds are sodium fluoride and lithium fluoride.

What is a Covalent bond?

Covalent bonding is the sharing of atomic particles between two substances. Covalent bonding means that one substance gives atomic matter to another. And vice-versa.

This exchange occurs between an organic and inorganic substance. When this occurs, it creates a new substance. One popular example is carbon monoxide. Other examples include sugar and water.

The atomic structures of these substances lend them to covalent bonding.

What is a Metalic Bond?

Metallic bonding occurs between positively charged atoms. This static electricity charge brings atoms together in a bond.

This bonding is what makes a metal more malleable and better for electrical work. The more flexible a metal, the easier it is to use for different electronic devices. But, it also allows differently charged atoms to create a bond for improved electrical flow.

Electrical Resistivity: A Measure of Conductivity

Image showing electrical conductivity type equations.

Electrical resistivity is a measure of how strongly a material resists electric current. If the material has a lower resistivity, this means it will conduct electric current more easily than a material with a high resistivity.

The resistivity of different size conductors at different temperature ratings are as follows:

Resistivity of Conductors

If we know the resistivity of a conductor we can calculate the resistance of that conductor given its length and Circular Mil Area (CMA). The equation relating them is as follows:

Resistance of a Conductor

Where p (rho) is the resistivity of the conductor, l is the length of the conductor, and CMA is the circular mil area of the conductor. We recommend you watch our video for deeper insight into this topic.

What is Ohm’s Law?

Ohm’s law connects voltage with the flow and resistance of electricity. The law studies the connection between the capacity of electricity to travel through a substance. It named for the German scientist, Georg Ohm, who first discovered its properties. He found that the movement of electricity through a substance relates to the voltage used.

The importance of this law is its connection with the electrical flow. A voltage of electricity can impact the flow of electricity. A stronger current can disrupt the organization of molecules within the materials. But, a good conductor permits the movement of the voltage with ease.

Why Good Conductors of Electricity Matters

An effective conductor of electricity helps to ensure the efficient use and transmission of electrical power. Coating wires with a good electrical conducting metal may seem counterintuitive at first. You might think it is dangerous to use a conductor on electrical equipment.

Whether in electrical wiring, connectors, or various electronic components, the molecular makeup of metals strikes an optimal balance, enabling them to efficiently transmit electrical currents while maintaining their stability.