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ELECTRICITY
What is electricity? To understand what electricity is, we need to learn a little bit about the nature of matter. What is all the stuff around us made of? EVERYTHING IS MADE OF ATOMS. Scientists have, so far, found 115 kinds of atoms. These are in The Periodic Table of Elements. Everything around us is made of different combinations of the elements. Electricity happens when the balancing force between electrons and protons (parts of the atom), is disturbed by an outside force. Electrons transmit an electrical charge through solid matter, such as metal, to produce an Electrical Current. Parts of an Atom
What are atoms made of? In the center of every atom is a "nucleus". In the nucleus there are two tiny particles called protons and neutrons. Orbiting around the nucleus are even smaller particles called electrons. Atoms from each element are different from each other because they have different numbers of protons, neutrons and electrons. Protons, neutrons and electrons are very different from each other and have their own properties. One of these properties is called "electrical charge". Protons have a "positive" (+) charge. Electrons have a "negative" (-) charge. Neutrons have no charge, they are neutral. The charge of one proton is equal in strength to the charge of one electron. When the number of protons in an atom equals the number of electrons, the atom itself has no overall charge, it is neutral. Positive and negative charges behave in interesting ways. Did you ever hear the saying that opposites attract? Well, it's true. Two things with opposite, or different charges (a positive and a negative) will attract, or pull towards each other. Things with the same charge (two positives or two negatives) will repel, or push away from each other. Protons and neutrons are held tightly together in the nucleus. However, electrons can move from one atom to another. Some materials hold their electrons very tightly together and do not move through them very well, such as, plastic, cloth, glass and dry air. these are called insulators. Other materials have some loosely held electrons, which move through them very easily. These are called conductors. Most metals are good conductors. Materials may be classified into one of three categories depending on their electrical conductivity (their ability to conduct a current). Conductors conduct electric charge better than semi-conductors, which in turn conduct better than insulators." Electrons can be moved from one place to another by rubbing two different materials together. If they are both insulators, electrons may transfer from one to the other. The more rubbing, the more electrons move, and the larger the charges built up. If you rub your hair with an inflated air balloon your hair stands on end Why does this happen? The answer is STATIC ELECTRICITY. Electrons (negative charge) have moved from your hair to the balloon. Now each of your your hairs has a positive charge, therefore they are trying to get away from each other!
When you walk over a carpet, electrons jump from the rug to you. Now you are charged with extra electrons. As you touch a door knob you get ZAP! The door knob is metal, therefore a conductor. When the electrons move from you to the knob you get a shock.
Electric Power Basic Ideas: http://projectsol.aps.com/power/power_making.asp To learn how electricity is generated visit: http://projectsol.aps.com/power/power_making2.asp Activities: Answer the following questions:
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