Science Force Grade 3 The purpose of this visit is to investigate magnetism: The lesson plan begins with a five-minute introduction by the Science Leader. The students will divide into four lab groups, and all groups will do the same experiment at the same time. Directions for the experiment will be reviewed during the Leader s initial presentation to the students. The Science Leader will gather the class together for the last five minutes of the visit, briefly reviewing and asking the students to explain their results. Teachers: Please divide the students into four lab groups. Students do not need to bring anything with them, and they will return to the classroom with one completed lab report per group. Volunteers: Please read this material, and arrive at the lab promptly to familiarize yourself with the experiment. Your roll will be to ensure safety and assist the students as they complete the experiment presented by the Science Leader. You will not be responsible for the class presentation, but it would be helpful if you read the information provided here before coming to the lab. Suggested Introduction by the Science Leader: Welcome to the Science Force Lab. This is a special time for you and our parent volunteers to investigate the exciting things you are learning in your classroom. The experiments you do during your Science Force visits are prepared and taught by your parents, and the equipment you use in this lab is purchased using the money from PTA. Brainstorm with students A force is a push or a pull. Gravity is a force. Today we will investigate another force that is hidden deep inside the earth. It makes a compass point north. It may be used to attract something to your refrigerator Do you know the name of that force? Instruction: Describe magnetism as a force. And like other forces, magnetism is a push or a pull. Ask the students to tell you about some uses for magnets. Describe how the earth is a magnet, (a very weak magnet), and although it can t pull steel boats to the bottom of the ocean, it can move the needle on a compass to point north. It also pulls the particles coming into the earth s atmosphere from the sun. This causes the northern lights that you can see in Alaska. Some substances can be attracted to a magnet, and others can t. It all depends upon how little charges, called electrons, like to orbit around inside a substance. (Use line dancing, like the electric slide, as an example.) When all the electrons get going in the same direction, it creates a magnetic force. Substances that contain iron and nickel are easily magnetized. That means they get going in the same direction when exposed to a magnet. There is a substance called neodymium (NE-oh-DIM-e-um) that really holds a strong magnetic force. We are going to use all kinds of magnets today. Some are ceramic magnets made with iron. A special neodymium magnet is also going to be used. It is very important that you do not put your neodymium magnet next to the magnet from another group. Your fingers will get pinched and we may not be able to get the magnets apart again. Look how strong this magnet is. It can even hold a paperclip through my hand or through my ear! You told me some uses for magnets. Now let me tell you about some others. Do you know
Science Force Grade 3 - page 2 that every electric motor runs because of an electric current and a magnet? Do you know that farmers feed magnets like this one, (show the cow magnet from the iron filing tube), to their cows? Why? Cows have lots of stomachs, and they feed they a magnet to the cow and it will stay in their first stomach. This way, when the cow accidentally eats nails or pieces of sharp metal that might be out in the field, the metal gets attracted to the magnet in their first stomach and it won t go on through the cow s digestive system and cause him to get hurt or sick! (When the cow is slaughtered, they remove the scraps attached to the cow magnet and feed that magnet to another cow!) So let s review what we are going to do today: Review the lab report and review all the labs they will be doing. Remind them that they will make a guess as to what will happen. This is called a hypothesis. Then they will record what actually did happen as their observation. #1 How Much Weight Can Each Magnet Lift? To test magnetic force, we will try to lift various cans with the ceramic and neodymium magnet. Do not let the students attempt the baked beans or the juice cans by themselves, as they may drop these, causing injury. Explain that the Coke cans were not attracted to either magnet because they are made of aluminum and that is not a substance that is attracted to a magnet. #2 How Many Paper Clips Will Each Magnet Hold? We will measure the strength of the ceramic and neodymium magnet by testing the number of paperclips that each magnet can be hold in a chain. #3 Talk about the force field around the magnet. Regardless of the strength of the magnet, the field though which the force is exerted is very small. #4 Is Money Magnetic? The first lab investigates the effect a neodymium magnet has on money. (Only the dollar bill is attracted.) #5 Does Water Stop a Magnetic Force? Use the magnet to raise and lower the paper clip inside a jar of water. Does the magnetic force go through water? (yes) #6 Will a Magnet Attract Pieces of Cereal? Pieces of a Potato Chip? We will float a small potato chip on a plate of water. Try to attract the chip by bringing the neodymium magnet close to it. It won t attract. Then try the same thing using a flake of cereal. The cereal contains iron, so it is attracted to the magnet. #7 Defying Gravity. Use a Pringle can with a window cut all along one side. A pencil through the top of the can supports paper clip which hangs inside from the a piece of floss looped over the pencil. The paperclip should hang about one inch from the bottom of the can. Place the neodymium magnet on the metallic bottom of the can. Watch it attract the paperclip. Slowly turn the can upside down and watch the paperclip defy gravity. Explain that the magnetic force is stronger pulling the clip up than the force of gravity is pulling the clip down. You may try this with the ceramic magnet, but it won t work.
Science Force Grade 3 - page 3 #8 Random Chaotic Motion. Next, thread a ceramic magnet on that swinging paperclip, placing the bottom of the can back down on the table. The students will observe the random, chaotic motion as the ceramic magnet is attracted and repelled by the neodymium magnet below. #9 Lines of Force. Use the iron filings tube to discuss magnetic lines of force. Pull the cow magnet in and out of the tube. Shake the tube to get the best effect. Show how the Force Field circles around the sides of the cow magnet, and toward either end of the magnet. Rotating through each lab group will be a special demonstrator showing lines of force surrounding a column magnet and a horseshoe magnet. The students will be illustrating their observations. (Shake the demonstrator to scatter the indicators before inserting the magnet.) Eddy Currents. We will also pass around an aluminum pipe. Hold the neodymium magnet next to the pipe to show the students that aluminum isn t attracted to a magnet. You would assume if you dropped the magnet down the pipe, it would just fall through. But is goes very slowly, like a force is acting on it. Actually, the magnet creates eddy currents in the pipe. A magnet creates a weak electric current that circles the pipe. That electric current creates a magnetic field, and that field repels the magnet as it is dropped. (Too much science here for first grade, but they will think the slowly dropping magnet is cool.) Like Poles Repel, Different Poles Attract. If time allows, let the students stack the ceramic magnets on a pencil so they will repel each other. Show them how each ceramic magnet has a side with a north pole and a side with a south pole. Opposite poles attract, but like poles repel. Some may be able to tell you how this works with Brio trains. The trains will only connect if faced in a direction so that the magnets with different poles together. Conclusion: Five minutes before the end of the lab, have the groups return everything to its place at the lab station, and they should remove their lab report, giving the adult their clipboard and pencil. In a group, the leader will review their observations and ask students to tell about their favorite part of the lab or tell about something they learned that they didn t know before they visited Science Force today. Thank the class for visiting Science Force, and thank the parents for their help. Lab Materials and Set-up: Five lab stations, each with: Money: penny, nickel, dime, quarter and dollar Neodymium magnet Ceramic magnets Unsharpened pencil Board to stick pencil in for stacking ceramic magnets
Science Force Grade 3 - page 4 8 oz. can (like tomato sauce) 8 oz. aluminum can (like a small Coke) 15 oz. can (like soup or tomato sauce) 12 oz aluminum can (like a regular size Coke) 28 oz. can (like baked beans or tomatoes) 46 oz. can (like tomato or grapefruit juice) 2-liter bottle full of water, ketchup packet with paperclip attached inside Potato chips Cereal flakes Plastic plate of water Box of paper clips Clear jar of water with paper clip inside Pringles can with one side cut away Pencil through holes near the top Paperclip hanging from pencil with a strand of dental floss Paper plate, empty Mag tube with cow magnet Lines of force demonstrators with horseshoe magnet and column magnet (to pass around to all the groups) Aluminum pipe (to pass around to all the groups) 2005 Vicki Templet, all rights reserved. Duplication and transmission by electronic means is permitted for single use implementation in a public school environment. Duplication or transmission by electronic means is not permitted under any other circumstance. If you choose to duplicate, transmit, and/or implement any of the material provided herein, you accept the responsibility for assuring the accuracy and the safety of the activities and content of this material. In accepting this responsibility, you must also understand that this material is provided to you at no charge. No revenue or profit should ever be required in exchange for this material. Also in accepting this responsibility, you understand that this material is a collection of many ideas from many different sources. This document may have gone through many revisions as it has been passed from school to school, and the written descriptions may have come directly from sources that are not suitably referenced. It is therefore advised that this material be used at your own risk, and that you assume complete responsibility for the single-use application of the ideas contained herein. For questions or to receive a current version of this document, please feel free to contact Vicki Templet, ScienceForce@bellsouth.net.
3 rd Grade Science Force Name: How strong are your magnets? Does it hold a: My Guesses: My Observations: 8 oz. Sauce 8 oz. Sauce 8 oz. Coke 8 oz. Coke 12 oz. Coke 12 oz. Coke 15 oz. Sauce 15 oz. Sauce 28 oz. Tomato 28 oz. Tomato 46 oz. Juice 46 oz. Juice How many paper clips can the cow magnet hold? My Guess: clips My Observation: clips How many paper clips can the strong magnet hold? My Guess: clips My Observation: clips Which money is attracted to the strong magnet? My Guesses: My Observations:
3 rd Grade Science Force Name: Does magnetic force go through water? My guess: My Observation: Float a small potato chip in water. Is it attracted to the strong magnet? Then try a small cereal flake in water. My Guesses: My Observations: Chip Chip Cereal Cereal What does the cereal contain that the potato chip does not? Observe the gravity defying paper clip in the Pringle can. Observe random chaotic motion by threading a ceramic magnet on the string in the Pringle can. Draw the cow magnet and illustrate the lines of force as shown by the iron filings Other Experiments: - Eddy currents as strong magnet is dropped down the aluminum pipe - Stacking magnets on the pencil to investigate how similar poles repel and different poles attract