Conductors and Insulators of Electricity
A major reason electricity works is because of conductors. First metal, water, tall trees and tall items are good conductors because lightning is attracted to them. These materials have many mobile electrons. Metal is an easy substance for lightning to travel through so metals are good conductors. However, rubber is a bad conductor because lightning bounces off of it. A bad conductor is called an insulator. An insulator has a few mobile electrons. It is important for us to know the difference between good conductors and insulators because if you're outside in an open field during a storm you will know where to go to be safe from the lightning. Truly, knowing the difference between conductors and insulators of electricity can save our lives.
Electricity is a type of energy found in nature.
It consists of electrons, and there is electricity in nature as well as electricity that is man-made. Scientists have found we can make electricity if we pass a magnet close to a metal wire, or if we put the right chemicals in a jar with two different kinds of metal rods. This is called an electromagnet. Scientists have observed that electricity seems to flow like water from one place to another, either as a spark or as a current in a metal. They now know that all matter has electric charge, but this is mostly cancelled out by the presence of matter with an opposite charge. We only see an effect when there is too much or too little electric charge in one place so that it is not cancelled out. Since the nineteenth century, electricity has been made into a useful creation that affects every part of our lives. Until then, it was just a curiosity or a force of nature seen in a thunderstorm. To be useful, electricity has to be made from different sources of energy such as by burning coal or oil or from wind or the sunshine or flowing water in a power station. Electricity arrives at our homes through wires from the places where it is made. It is used by electric lamps for producing light, electric heaters to produce heat, etc. It is also used by many devices such as washing machines, electric cookers, etc. for doing work. In factories, electricity is used for running machines and computers. The people who deal with electricity and electrical devices in our homes and factories are called "electricians". Electricity works because electric charges push and pull on each other. There are two types of electric charges: positive charges and negative charges. Similar charges repel each other. This means that if you put two positive charges close together and let them go, they would move apart. Two negative charges also repel. But a different charges attract each other. This means that if you put a positive charge and a negative charge close together, they would smack together. A short way to remember this is the phrase opposites attract, likes repel. Electric charges push or pull on each other if they are not touching. This is possible because each charge makes an electric field around itself. An electric field is an area that surrounds a charge. At each point near a charge, the electric field points in a certain direction. If a positive charge is put at that point, it will be pushed in that direction. If a negative charge is put at that point, it will be pushed in the exact opposite direction. All the matter in the world is made of tiny positive and negative charges. The positive charges are called protons, and the negative charges are called electrons. Protons are much bigger and heavier than electrons, but they both have the same amount of electric charge, except that protons are positive and electrons are negative. Because "opposites attract," protons and electrons stick together. A few protons and electrons can form bigger particles called atoms and molecules. Atoms and molecules are still very tiny. It is impossible to see them without a very powerful microscope. Any big object, like your body, has...
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