Energy comes from charged particles that are moving around. Have you held a balloon or a comb over someone's head to watch his hair stand up straight? That's static electricity and electrically charged particles. <br><br>Static electricity builds up on certain materials. Other materials, though, let electrical charges flow through them. This creates an electric current. Electric current travels very easily through metals like copper, gold, silver, and aluminum. We call materials that an electric current flows through easily conductors. Water is also a good conductor of electricity. <br><br>Because metal is a good conductor of electricity, electrical wires are often made out of metal. Wiring can also be made out of non-metal materials, such as graphite. <br><br>Conductors have to be enclosed in a material which is called an insulator. Insulators do not allow an electric current to pass through them. The rubber coating that you see on electrical cords covers the metal. The electric current stays inside the cord so we can direct the current to the appliance that needs power. Other good insulators are glass and some plastics.<br><br> Rubber is a type of good insulators. 2. Insulators let electric currents pass through them easily. 3. Conductors do not let electric currents flow through them. 4. Electric currents come from charged particles moving around in the air.
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