Ever Wonder How the World Works? Wonder Wall: Do you ever wonder how electricity works? How does it get to your house? Get a sticky note. Jot down any questions you have about electricity. GPS Standards • S5P3.A- Investigate static electricity. • S5P3.B- Determine the necessary components for completing an electric circuit. • S5P3.C- Investigate common materials to determine if they are insulators or conductors of electricity. • S5P3.D- Compare a bar magnet to an electromagnet. Unit Essential Questions • What is static electricity? • What are the components needed to complete an electrical circuit? • What are insulators and conductors, and what are some examples of each? • What is a magnet? How do I compare/contrast a bar magnet and an electromagnet? Lesson 1: What is Static Electricity? EQ: What is static electricity? Vocabulary: static electricity, electric charges, protons, electrons, attract (attraction), and repel (repulsion) Let’s do an experiment! Look at your handout, and make some predictions! Static Electricity Static electricity is a buildup of electric charges on an object. It can “jump” from one object to another. electric charges Electric charges are tiny particles that carry units of electricity. There are two kinds of electric charges, positive(+) and negative(-). protons Protons are positively charged particles located inside the nucleus of an atom. electrons Electrons are negatively charged particles circulating outside of the nucleus. attract (attraction) Unlike charges attract one another, meaning they pull toward one another. repel (repulsion) Like charges repel one another, meaning they push each other away. Preview: BrainPop! Electricity Read interactive textbook pp. 140-143. Optional: textbook pp. 228-233 What is Static Electricity? Static electricity is a buildup of electric charges on an object. Unlike electricity used in your home, static electricity doesn’t flow. If the charge is strong enough, static electricity can “jump” from one object to another. The shock you feel is called a discharge. What connection can you make from what we have already learned? Static electricity is what causes dust to collect on your television screen at home! BrainPop! Static Electricity Where Does Static Electricity Come From? Everything is made of matter. All the equipment and supplies located in your classroom are made of matter (even you). Matter is made up of tiny particles. These tiny particles contain different kinds of electric charge…positive (+) and negative(-), and neutral (no charge). Charging an Object When two objects rub against each other, some electrons may move from one to the other. The object that gains electrons will then have a negative charge. The other object will have a positive charge. So… Charging an Object If you rub a balloon on your hair, electrons move from your hair to the balloon. The balloon will have a negative charge (-). Your hair would have a positive charge (+), because electrons have been taken away. If you bring the balloon near a wall, it will stick to the wall because the wall will have an opposite charge (+). Electric Force Electric Force is the push or pull between charged objects. Objects that have like charges repel, or push against each other. Objects that have unlike charges attract, or pull on each other. Electric Force Electric forces and magnetic forces are very similar... opposite poles/forces attract each other. Objects do not have to actually touch to exert either an electric force or a magnetic force on each other. Plasma Balls Touch The Power Of Static Electricity And Create A Living Work Of Ever-Changing Art The Plasma Globe, or Inert Gas Discharge Tube, as Nikola Tesla (it's inventor) first called it, is perhaps one of the most beautiful manifestations of plasma (4th State of Matter). Also known as "Plasma Spheres", "Lightning Globes", "Thunder Domes", and others, these glass spheres with dancing streams of plasma inside them have been looked at, and admired, by people all over the world, in sci-fi movies, science museums, and even some shops. A plasma ball is a glass globe filled with low pressure gases such as neon, argon or xenon. An electrode is placed in the center of the globe and connected to the power supply which gives a high-voltage, high frequency, alternating current. Balloon Experiment Experiment with static electricity. using balloons. Tear little pieces of paper…rub the balloon on your head, then hold it near the bits of paper. What happens? Have Fun! Summarizer In your journal, answer the following question. Be prepared to share your answer! A charged balloon attracts small bits of paper. Why does this happen? How is it like a magnet attracting paper clips? Think…Pair…Share! Lesson 2: Electricity and Complete Circuits What Makes a Circuit? Essential Question: What are the components needed to complete an electrical circuit? Vocabulary: simple circuit, series circuit, parallel circuit, terminal, switch In order for electricity to flow, a closed circuit is required. The following image shows a closed circuit with flowing electrons. electric circuit The pathway that electric current follows is called an electric circuit. pathway Simple Circuit Parallel Circuit BrainPop! Electric Circuits Series Circuit Simple Circuit The simplest electric circuit needs an energy source and a material that electrons can easily flow through. All components need to be connected to complete the circuit. series circuit The parts of an electric circuit are connected so that electric current passes through each part, one after another, along a single pathway. Series Circuit In a series circuit, the electric current flows in a single path… first through one bulb (or battery), then through the next. The more bulbs that are connected in series, the more dimly all will glow. If one bulb burns out or is removed, all the bulbs in the series go out (because the path would be broken). Parallel Circuit •In a parallel circuit, the different parts of the circuit are connected in separate branches. The electric current travels to each branch. •A parallel circuit is more difficult to put together than a series circuit, but it has an advantage. •What is the advantage? If one path (branch) is broken, the current will continue to move along another path! If there are multiple bulbs connected in a parallel circuit and one bulb burns out…the other bulbs will stay lit because they will continue to receive the electric current passing through the wires. parallel circuit The parts of a parallel circuit are connected so that electric current passes along more than one pathway. Battery or Energy Source Object that uses the energy The Switch Conductor…usually wire Please note that a circuit can still be complete without a switch. The switch is for convenience of turning the circuit on or off. The Battery or Energy Source A battery is an energy source often used in a circuit. It provides the “push” to keep electrons moving in a circuit. A simple battery has two parts. One part tends to give up some of its electrons. The other part tends to take in electrons. If you connect the ends of a wire to the top and bottom of a battery, electrons will flow through the circuit. A terminal is a place on a battery where electrons go in or out. Often, the positive terminal, where the electrons go in, is on top. The negative terminal is on the bottom. Some batteries have both terminals on top. BrainPop! Batteries The Conductor…Usually Wire The wire used in a circuit is often made of copper. Copper is a metal. The electrons can easily move from atom to atom in a metal. The wire should have a plastic or rubber coating on it. The electrons cannot easily go through the coating. It lets you safely touch the wire. The Switch A switch is a device that can open or close a circuit. The bulb in this picture is not lit because the switch is flipped up. An open circuit is an electrical path that is not complete. Electrons will not flow when the circuit is open. The bulb in this picture is lit because the switch is down. The circuit is closed and the circuit is complete. A closed circuit allows electrons to flow. The Bulb or Object to Receive the Energy Most circuits have more in them than just a wire and battery. For example, imagine a circuit that has a bulb. A bulb has a thin wire called a filament inside. This wire is so thin that electrons can hardly pass through. When they do, the wire becomes hot. It begins to glow. This glow is the light you see from a bulb. Adding To and Taking Away with Simple Circuits You can add more bulbs to a simple circuit. Current will flow first through one bulb and then through the other. Devices such as bulbs or buzzers resist the flow of electrons. Adding an extra bulb to a circuit resists the flow even more. As a result, two bulbs in a circuit glow less brightly than one bulb alone does. A switch does not resist the flow of electrons. Taking a switch out, or adding another switch, will not affect the brightness of the bulb. What do you think would happen if you remove the battery or if you remove one of the bulbs? Junior Electrician: Current Electricity (15 min.) United Streaming Video Presentation Problems? Look in the folder for the video. Summarizer In your journal… Reflect on the experience of building electrical circuits. What procedures did you follow? Were you able to build a “working” simple circuit? Did you have any problems? Explain and draw a picture to demonstrate how a simple circuit works! Lesson 3: Conductors and Insulators Lesson 3: Conductors and Insulators EQ: What classifies a material as a conductor or insulator of electricity? What are examples of each? Vocabulary: conductor, insulator, electric current (electricity) electric current (electricity) An electric current is the flow; or movement, of negative charges through a material. Movement of electrons along the electric pathway! What is Electric Current? For electricity to be useful, it must be moving continuously. So static electricity is not very useful. Negative charges can move freely from place to place in a solid. An electric current is the flow; or movement, of negative charges through a material. The energy provided by the moving charges is called electrical energy, or simply electricity. Electricity can be used to do work. However, the energy of the moving charges that make up electricity must be controlled. You must be able to make electricity move and stop moving when you want. And you must be able to control where it goes. When you plug something into an outlet, you tap into an electric current. The electricity flows through the plug and into the object you plugged in BrainPop! Current Electricity What is Electric Current? Once electricity reaches the place where it is to be used, it is changed into some other kind of energy, such as light in a lamp, heat in a toaster, or motion in a fan. Think about how energy is used and controlled in the school. Cords are plugged into outlets. Switches are flipped, and electric charges move or stop moving through wires. Dials and knobs are turned to change the amount of charge that moves through the wires. This is controlled energy. Electricity being used in the home. Conductors Wires are the pathways through which negative charges flow. Wires are made of materials that carry these charges. A conductor is any material that allows negative charges to move through it. Metals make the best conductors. Copper is the most common metal used for that purpose. The wires used in your school and in your home are probably made of copper. You may be familiar with the expression “live wire.” The word live is used to describe any conductor in which charges are moving. Moving charges can be dangerous. Your body is a good conductor. If you were to touch a live wire, the charges in the wire would move through your body and you would receive an electric shock. If the wire is carrying enough current, the shock can cause serious injury, or even death. conductor A conductor is any material that allows negative charges to move through it. Metals Watch make the best http://www.youtube.com/w conductors. atch?v=-wj2Oh50wsA for a video clip from A Christmas Story (tongue on pole) to show heat transfer. People are good conductors of electricity, especially if they are in contact with water on a damp floor or ground. Never use an electric appliance in a tub, shower or pool. Never touch an electric cord or appliance while your hands are wet. Insulators Negative charges do not flow freely through some materials. These materials are called insulators. Some good insulators are rubber, wood, glass, and certain plastics. To make electricity safe to use, conductors and appliances are covered with an insulator. This covering is called insulation. The negative charges can continue to move freely through the conductor, but the insulation will protect a person from the live wire. As long as negative charges have a complete path to follow, they will continue to move through a conductor. But where do all these negative charges come from? Somewhere, there is a device that provides a steady supply of negative charges. It may be a huge generator at an electric power plant, or it may be the chemicals in a tiny cell that runs a wristwatch or calculator. The metal cables and metal clips of the jumper cables are conductors. You are protected by rubber insulation. insulators • Materials that electric charges do not flow through easily are called insulators. In your journal…Sort the following items as conductors or insulators of electricity. Discuss with a partner. Can you think of others? Other Resources to Explore Quia - Electricity: Conductors and Insulators Matching Game Lesson 4: Magnets “Bar Magnets and Electromagnets” Lesson 4: Bar Magnets Vs. Electromagnets Essential Question: What are bar magnets and electromagnets, and how can I compare and contrast them? Vocabulary: magnet, magnetic field, electromagnet, generator, and motor Just What are Magnets? A magnet is an object that can push or pull on iron and a few other kinds of metal without touching the metal. Each end of a magnet is called a pole. The poles of a magnet are usually labeled N for north and S for south. Some magnets have a bar shape. Magnets with a U shape are called horseshoe magnets. If the north poles of two magnets are close, the magnets repel, or push apart. The magnets also repel if the south poles are close. If a north pole and a south pole are positioned toward each other, the magnets attract, or pull together. magnet A magnet is an object that attracts iron and certain other metals. magnetic poles The force of a magnet is greatest at two areas called the magnetic poles. Magnetic Field A magnetic field is the area around a magnet where it can push and pull on other magnets. A magnetic field is all around a magnet, but it is strongest at the poles. The push or pull from a magnet is strongest close to the magnet. The strength of the field is weaker farther from the magnet. BrainPop! Magnetism Did you know? • No matter how many times a bar magnet is cut in half, there is always a north and south pole, even in the smallest piece. generator A generator is a device that uses magnetism to convert energy of motion into electrical energy. motor An electric motor is a device that changes electrical energy into energy of motion. Inside of a motor http://www.physics.uiowa.edu/~umallik/adventure/nov_06-04.html Electromagnets Magnets and electricity are related. An electric current produces a magnetic field. When a current flows through a wire, a magnetic field surrounds the wire. If you form the wire into loops, the magnetic field is like that of a bar magnet. Just like a magnet, the wire loops with a current have a north pole and south pole. The magnetic field is strongest at the poles. You can increase the strength of the magnetic field if you add more loops. You can also increase the field if you increase the current in the wire. BrainPop! Electromagnets electromagnet An electromagnet is a strong temporary magnet that uses electricity to produce magnetism. Making an Electromagnet An electromagnet is a magnet made by winding a wire with a current around an iron bar. When the iron bar is placed in the looped wire, the iron itself has a magnetic field. This makes the field of the looped wire stronger. You can make an electromagnet if you loop wire around an iron nail and attach the ends of the wire to a battery. The current in the wire will cause the iron and wire to be a magnet. You can then use the electromagnet just as you would use a bar magnet. It will attract paper clips and other iron objects. Did you know you already use electromagnets ? Electromagnets are found in may devices. Doorbells, computers, audio speakers, and telephones have electromagnets in them. A crane uses an electromagnet to pick up heavy loads of iron or steel. A wire coil in an electric motor spins because it is an electromagnet. Comparing a Bar Magnet and an Electromagnet Think about what you have learned about basic bar magnets and electromagnets. How are these magnets similar? Comparing a Bar Magnet and an Electromagnet 1. Both types of magnets have a north and south pole. 2. The field around them is strongest at these poles. 3. They both attract iron filings and other magnetic objects. Advantages of Electromagnets Over Bar Magnets They can be turned on and off by turning the current on and off. They can be made stronger or weaker by either changing the strength of the battery or by changing the number of wire loops. The direction of the field can be changed (switching the poles) by switching the ends attached to the battery. Magnets (17 min.) United Streaming Video Presentation Problems? Look in the folder for the video . Let’s Try to Build an Electromagnet Use the handout provided in class to build an electromagnet! Summarizer In your journal… Draw a picture of a bar magnet and an electromagnet. Describe the similarities between the two magnets. https://www.vtunnel.com/index.php/1010110A/ecbc83adfa346c8e3be5486d78a1d6130682de97e95b4bfb2cc1249de2b5a6d5cfb68c7525821323c0c d8039616e213d888652bcb8ed721275c0086d95342c18696