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Conductors and Insulators

This lesson is about conductors and insulators. Learn about lists of heat conductors, lists of heat insulators, lists of electrical conductors and lists of electrical insulators.



Examples of Insulators

Examples of Insulators


Conductors and Insulators


We can define conductors and insulators in relation to heat and electricity.


Conductors can be heat conductors and electrical conductors. Insulators can be heat insulators and electrical insulators.


Conductors and Insulators of heat


Heat Conductors (Conductors of Heat)


Heat conductors or conductors of heat let heat flow through them easily.


Have you ever tried to stir boiling soup using a metal spoon? If you have tried so, you know how quickly heat energy flows from the hot soup, through the spoon, to your hand. Do you remember; how your fingers began to get hot??? This is because heat travels faster through metal. Substances like metal are called conductors.


Heat Conduction


The movement of heat through a solid heat conductor is called heat conduction.


For example;

The metal spoon conducts heat from the hot soup to your hand.


Good Heat Conductors

  • Metal is a good heat conductor because it lets heat flow through it easily.
  • Copper and silver are the best heat conductors.
  • Copper conducts heat ten times better than iron.
  • When heat travels by conduction through a heat conductor, the heat is passed on from one atom to the next. The heat flows, the heated atoms don’t!

Examples of heat conductors

  • Aluminium
  • Brass
  • Bronze
  • Copper
  • Gold
  • Graphite
  • Iron
  • Mercury
  • Steel
  • Silver


Heat Insulators (Insulators of Heat)


Heat insulators or insulators of heat don’t let heat flow through them.


Let’s get back to our example.


If you have used a wooden spoon or a spoon with a plastic handle, you know how easier it is to stir the hot soup, by experience. This is because neither wood nor plastic conducts heat. Substances like these are called insulators.


Good Heat Insulators

  • Wood, plastic and air are some of the examples of heat insulators.
  • Gases are poorest heat conductors. In other words, they are the best heat insulators. Air is a mixture of gases. This is why air is a good insulator.

Examples of heat insulators

  • Wood
  • Plastic
  • Glass
  • Rubber
  • Fabric
  • Cork
  • Ceramic
  • Styrofoam
  • Porcelain
  • Air

Uses of heat conductors and insulators


Now you can understand that heat conductors and insulators can both be useful, but for different jobs. For example; the bottom of a saucepan may be made from a metal, like iron or aluminium, which lets heat flow quickly from the cooker to the food inside. But its handle is likely to be wooden or plastic. These materials won’t let heat flow to your fingers and burn them.


Heat conductors and heat insulators are also called thermal conductors and thermal insulators.


Conductors and Insulators of electricity


Electrical Conductors (Conductors of Electricity)


Electrical conductors or conductors of electricity let heat flow through them easily. Electrical conductors block the flow of electricity.


For Example;

Copper is a metal that conducts electricity well. Most electrical wires are made of copper.

Good electrical conductors

  • All metals conduct electricity, but some metals are better than others.
  • Copper, aluminium, gold and silver are very good conductors.
  • Silver conducts electricity better than copper does, but silver is too expensive to use for electrical wiring.

Examples of electrical conductors

  • silver
  • aluminium
  • gold
  • copper
  • graphite
  • steel
  • brass
  • bronze

Electrical Insulators (Insulators of Electricity)


Electrical insulators or insulators of electricity don’t let electricity flow through them.


Let’s get back to our example.


You know that most electrical wires are made of copper. But if you touch these wires you can get a shock, which is extremely dangerous. That is why all electrical wires are insulated with a plastic cover. Plastic is an electrical insulator. It does not conduct electricity at all. So you can touch the electric wire without getting a shock because of the plastic cover.


conductors and insulators - copper cable

All electrical wires are insulated with a plastic cover

Good electrical insulators

  • Plastic, rubber, wood and glass are all good insulators.
  • Electrical wires are covered in plastic and plugs and sockets are made of plastic for the same reason.
  • The plastic insulates your fingers from the electricity flowing through the inside of the plug.
Conductors and Insulators - plug

The plastic insulates your fingers from the electricity flowing through the inside of the plug

Examples of electrical insulators

  • glass
  • plastic
  • rubber
  • porcelain
  • air
  • paper
  • wood
  • fabric
  • cork
  • ceramic
  • wool