Conductors and Insulators

The average person uses a lot of electricity in the many things they do every day. We are used to being able to turn on a light, watch the television, use our mobile devices, and stream music or videos. Because electricity is so much a part of our lives, we should know something about it.

Different materials and objects let electrical current flow more freely than others and these are called “conductors.” The materials that are resistant to electrical current flow are called “insulators.”

A piece of resistive material with electrical contacts on both ends.

Both are important in electricity because we need some materials to allow good energy flow and others to slow or stop it to protect us and our surroundings from the dangers of electricity.


Electrical conductors are very important for electricity to work. The conductors are made up of atoms that let the current flow easily.

The outer electrons are loosely held together so that they can move freely through the material when you apply an electrical charge.

We are familiar with some of the most conductive materials because many of these are metals. The metals have electrons in the outer atom layers that share back and forth in a fairly free method.

Silver is one of the most conductive materials, but it’s too expensive to use in large quantities in electrical equipment.

Another material that is a good conductor is copper. It’s used in a lot of older electrical wiring and circuits. Copper wiring is slowly being replaced with better and more efficient conductors that don’t corrode.


Resistance is the measurement of a material to see how well it opposes the electrical current flow. Conductance is the opposite; measuring how easy the flow of electrical current happens.

In the electrical profession, they use the letter “G” when talking about conductance and the letter “R” when representing resistance.


If you want the flow of electricity to happen without any resistance, you look for materials that are called “superconductors.” Electricians list these with “0” electrical resistance.

So far, all of the superconductors that scientists have discovered need extremely cold temperatures to be superconductors. These can be a low as -234 degrees C.


Since we can’t always have extremely cold temperatures to conduct electricity for the superconductors, there are materials that allow good conductivity as well as the ability to have the electrical current flow controlled.

Semiconductors are very important in electronics and we use them every day in our mobile phones and computers. We need to be able to control the electrical current flow so that it goes in only one direction or only happens under specific situations.

Superconductors give us that ability and the most common superconductor used today in electronics is silicon.


Electricity flow can be extremely dangerous so we need to have materials that stop or oppose the electricity flow. These are call insulators and we see them on the coating of the wires and cables that carry electricity to our televisions and computers.

This is a kind of rubbery substance that insulates and keeps us safe. Other good insulators are wood, the air, paper, and glass.

Fun Facts about Electrical Conductors and Insulators

  • A majority of the electronics companies started and exist today in “Silicon Valley,” California; which is a nickname after the silicon semiconductor.
  • Gold is too expensive to use in large quantities, but it does have a low resistance and is used in small amounts in computer processing boards.
  • Most of the electrical conductors are also good at conducting heat.
  • The ability for a material to be a good conductor also depends on how high the temperature is; the higher the temperature, the lower the material is for good conductivity.
  • Aluminum is a good conductor and is used a lot for long electric transmission lines.
  • Iron isn’t used in our homes for wiring, but because it can hold heat it’s used in our electrical heaters.
  • When a computer or phone is discarded, salvaging companies will take it apart and get the valuable metals such as gold or silver that are in the chips or boards.


What is a conductor?
materials and objects let electrical current flow more freely than others

What is an insulator?
materials that stop or oppose the electricity flow

What are the alphabetic letters used to represent conductance and resistance?
G and R

Why are superconductors important?
they let the electrical flow happen with ‘0’ resistance

What is the name of the location in California where a lot of electronic companies are found?
Silicon Valley