Explainer

Some materials let electric charge move easily, while others strongly resist that movement. Metals have mobile electrons, whereas an ordinary insulator has very few charges available to carry current under normal conditions. That distinction helps explain why wires use a conducting core and an insulating covering.

The key ideas

  • Conductors have mobile charge carriers.
  • Insulators strongly resist current under ordinary conditions.
  • Insulation has limits and can break down.

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Original recording: TikTok, 2023-02-02.

Video transcript

Read the original recording’s transcript

Automatically transcribed from the original recording. Small transcription errors may remain.

Why does rubber prevent you from being shocked? How does it tame electricity so well? Well to get a handle on this, we need to understand how electrical charges flow through material. So electrons, those little negatively charged particles, are what determine whether a material is a conductor or an insulator. In a conductor, electrons flow freely, making it easy for electrical charges to flow through the material. But in an insulator, like rubber, the electrons are more tightly bound to the atoms, making it more difficult for electrical charges to flow through.

So imagine electrons or electrical charges like you on a bicycle. You're cruising fast downhill and all of a sudden, you hit a deep puddle of mud. You'll probably come to a screeching halt and it's going to be a real challenge to get that bike moving through the mud again. In the same way, rubber and other insulating materials slow down electrical charges, but don't stop them completely. This is because the electrons in insulator materials are held in place by the strength of the chemical bonds between atoms. These bonds are much stronger than the electrical forces that would otherwise make the electrons

flow through the material. This creates a high resistance to the flow of electrical current, making it difficult for electrical charges to flow through an insulator. And to top it all off, the electrons in insulator materials are further away from the positively charged nucleus, which further reduces their ability to move. In rubber, the chemical bond is strong because the atoms have a strong attractive force, bond energy that holds them together. The greater the bond energy, the stronger the bond and the harder it is to break it. A strong chemical bond helps to keep the atoms of a molecule or compound

together, maintaining the material's structural stability and allowing it to have specific properties and behaviors, like insulation.