LEARNING
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LIMBS
Conductors and Insulators
Vocabulary Grade Level: 4 Overview: 
LIMBS LIMBS Interna onal is a nonprofit organiza on which provides prosthe cs to amputees in underdeveloped countries. To achieve this goal the organiza on partners with exis ng clinics around the world. In this ac vity, students will gather data about prosthe c materials and their conduc vity proper es. 
Conductor 
Insulator 
Electric Circuit 
Electromagne c Field In this lesson students will: 
Atom 
Watch the LIMBS Interna onal video 
Electron 
Discuss how important the ability to walk is 
Closed Circuit 
Use a chart to track conduc vity proper es 
Open Circuit 
Observe how insulators and conductors respond in a circuit 
Current 
Compare and contrast insulators and conductors proper es 
Electricity Bonus Word: Students learn: 
Prosthe c 
Not everyone has the ability to walk, but LIMBS is helping them walk again 
Charts can be used to categorize and group materials during experiments 
Conductors all have similar proper es 
Insulators all similar proper es 
Conductors allow energy to pass, while insulators prevent energy from passing. 
Electricity travels in a closed path called a complete circuit 
Electromagne c fields can be created by passing electricity through a wire and can be turned on and off Students will be able to: 
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Understand that not everyone is the same and to empathize with others. Differen ate between conductors and insulators. Demonstrate that electricity travels in a closed path. Create an electrical circuit. Explore an electromagne c field. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
Math and Science Content Tie‐In: Students will collect data, analyze proper es and draw valid conclusions by u lizing the scien fic method Levels of Thinking: Analysis and Modifica on 
seeing pa erns  organiza on of materials by their proper es  iden fica on of components to the prosthe c through observa on Texas Essen al Knowledge and Skills: SCIENCE 4.6 Force, mo on, and energy. The student knows that energy exists in many forms and can be observed in cycles, pa erns, and systems. The student is expected to: B differen ate between conductors and insulators 5.6 Force, mo on, and energy. The student knows that energy occurs in many forms and can be observed in cycles, pa erns, and systems. The student is expected to: B demonstrate that the flow of electricity in circuits requires a complete path through which an electric current can pass and can produce light, heat, and sound 6.6 Ma er and energy. The student knows ma er has physical proper es that can be used for classifica on. The student is expected to: (A) compare metals, nonmetals, and metalloids using physical proper es such as luster, conduc vity, or malleability STAAR Connec on: Grade 5 STAAR science test requires students to apply scien fic knowledge related to energy where students apply the knowledge that various materials conduct electricity and can reason which material would best conduct energy. 2. Which of these is the best conductor of electricity? F Glass rod G Co on string H Plas c tubing J Copper penny Source: h p://www.tea.state.tx.us/student.assessment/staar/testques ons Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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Materials: 
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Conductors and Insulators
Chart paper Markers Paper bags Items for paper bags Student Science Journals Day 1 Introduc on: Show and discuss the LIMBS video (h p://youtu.be/Iqv35cUUDL4). Read the founda on knowledge for the students to get the overview of electricity, conductors and insulators. (See a ached at end of lesson) Now ask: 
What does LIMBS interna onal do?  Why it is important to be able to walk? Discuss the emo onal impact of losing a limb and how that impacts their daily lives. Transi on into how easy it is to walk into the kitchen and open a refrigerator door and grab something to eat. Explain that like a refrigerator has moving parts so do our limbs. Then open the discussion into what types of materials would be good to build and create a new limb. 
What type of material can be used as a conductor? 
What type of material can be used as an insulator? 
What is a circuit? 
How can we create an electromagne c field? Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
Student Ac vity: Hands on ac vity: In this ac vity, students will determine the temperature of water in different cups to inves gate the role of conductors and insulators and how the material that prosthe cs are made of need to remain constant, not able to melt easily, and be useful long term. Prepara on Gather a variety of cups for each group to test their ability to conduct or insulate heat. You may wish to have each group conduct the tests with different materials if you have more than three or four types of cups available. Alterna vely, each group can be in charge of one cup and measure the changes accordingly. Exercise cau on with hot liquids and be sure students are aware of how to handle the cups carefully. You may wish to make a table on the board as an example for students to record their results, lis ng 5, 10, and 15 minute intervals, cup materials, and then gives room for students to enter each temperature. Background for Teacher Conductors and insulators work in different ways. Conductors permit the flow of heat or electrical energy, such as with metal wires, glass, or paper cups. Insulators on the other hand prevent the flow of heat or electrical energy, such as with double paned windows, travel mugs, or Styrofoam. Substances that insulate well will show a smaller change in temperature here than those that conduct energy well. Procedure Ask students why we might want to keep hot things hot or cold things cold. Allow me to respond. Introduce the cups to students, and explain that they will be determining which are the best materials for keeping our hot water hot the longest. A er adding hot water to each, have students record the ini al temperature. Then have students record the temperature a er 5, 10, and 15 minutes. Reflect on the temperature changes in each cup. Those with larger changes let heat pass, so are be er conductors. Those with the lowest temperature change are insulators. Have student groups move to alterna ve groups to answer each ques on. Groups will either list the answers or build the graph, and then all students return to their original group to share their results. Explain to the children that materials that are making up these prosthe c limbs must be durable and yet affordable since they are being used in remote undeveloped countries that have limited funds and resources. In order to achieve this balance LIMBS uses a plas c called Delrin to make the LIMBS knee. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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Conductors and Insulators
Ask: What are the benefits of using Delrin? Possible answers: 
It is waterproof 
Lightweight 
Does not conduct heat 
Is affordable and available around the world Class follow‐up ac vity: Reflect in their notebooks how having a properly made limb changes lives. How would they feel if they had received a prosthe c limb? Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
Materials: C‐leg video (h p://www.youtube.com/watch?v=TUa9WmSHqdk) 
Small light bulb (or a flashlight bulb) 
2 ba eries (with the correct voltage for your light bulb) 
2 alligator clip wires or aluminum foil 
Paper clips 
Electrical tape (Scotch® tape also works) 
Bulb holder (op onal) 
Ba ery holders (op onal) Day 2 Introduc on: Student will iden fy the different between expensive, high‐end prosthe c and the products that LIMBS provides. Watch the video describing how one of the best knees in the world (the C‐leg) func on: h p://www.youtube.com/
watch?v=TUa9WmSHqdk 
The C‐leg can cost up to $100,000 
A LIMBS leg costs $300 Discussion: Ask: How is the C‐leg different than the LIMBS leg? 
It has microprocessors that are constantly adjus ng the leg’s movement during walking  It is more expensive  It needs a lot more maintenance it something goes wrong  It is not waterproof The goal of LIMBS is to bridge the gap between quality and affordability. The LIMBS knee func ons just as well as a $2,000 knee that you can buy in the U.S. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
Student ac vity: Build a simple circuit A circuit is a path that electricity flows along. It starts at a power source, like a ba ery, and flows through a wire to a light bulb or other object and back to other side of the power source. You can build your own circuit and see how it works with this project! Part 1 ‐ Making a Circuit: 1. Connect one end of each wire to the screws on the base of the light bulb holder. (If you're using foil, ask an adult to help you unscrew each screw enough to fit a foil strip under it.) 2. Connect the free end of one wire to the nega ve ("‐") end of one ba ery. Does anything happen? 3. A ach the free end of the other wire to the posi ve ("+") end of the ba ery. Now what happens? Part 2 ‐ Adding Power 1. Disconnect the ba ery from your circuit. Stand one ba ery so that the "+" end is poin ng up, then set the other ba ery next to it so that the flat "‐" end is poin ng up. Tape around the middle of the ba eries to hold them together. 2. Set a paperclip across the ba eries so that it connects the "+" end of one to the "‐" end of the other. Tape the paperclip in place with a narrow piece of tape (do not tape over the metal ba ery ends). 3. Turn the ba eries over and tape one end of a paper clip onto each of the ba eries. Now you can connect one wire to each paper clip. (The bo om of the ba ery pack should only have one paper clip — do not connect a wire to it.) 4. Connect the free ends of the wires to the light bulb. Discuss the similari es between the simple circuits, how our body’s nervous system helps us walk and how the C‐leg func ons. 
Homework follow‐up ques ons 
Why are electric cords, such as on a toaster or a lamp, covered with a rubber coa ng? 
How does electricity move through wires? 
When we turn electrical devices on and off, we are using open and closed circuits. What happens when you turn off the television? 
How would you create and electromagne c field? 
What type of tools, appliances or devices might require an electromagne c field for its use? Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
Materials: 
Circuit with light bulb & 2 ba eries  Extra alligator clip wire (or aluminum foil wire)  Objects to test (made of metal, glass, paper, wood, and plas c) Day 3 Introduc on: In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most nonmetallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them. "Conductor" implies that the outer electrons of the atoms are loosely bound and free to move through the material. Most atoms hold on to their electrons ghtly and are insulators. In copper, the valence electrons are essen ally free and strongly repel each other. Any external influence which moves one of them will cause a repulsion of other electrons which propagates, "domino fashion" through the conductor. Simply stated, most metals are good electrical conductors, most nonmetals are not. Metals are also generally good heat conductors while nonmetals are not. Student Ac vity: Insulator or Conductor? Materials that electricity can flow through are called conductors. Materials that stop electricity from flowing are called insulators. You can find out which things around your house are conductors and which are insulators using the circuit you made in the last project to test them! What To Do: 1. Disconnect one of the wires from the ba ery pack. Connect one end of the new wire to the ba ery. You should have two wires with free ends (between the light bulb and the ba ery pack). 2. You have made an open circuit and the bulb should not light up. Next, you will test objects to see if they are conductors or insulators. If the object is a conductor, the light bulb will light up. It is an insulator, it will not light. For each object, guess whether you think each object will complete the circuit and light up the light bulb or not. 3. Connect the ends of the free wires to an object and see what happens. Some objects you could test are a paper clip, a pair of scissors (try the blades and the handles separately), a glass, a plas c dish, a wooden block, your favorite toy, or anything else you can think of. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Conductors and Insulators
What's Happening? Before you test each object, guess whether it will make the light bulb light up or not. If it does, the object you're touching the wires to is a conductor. The light bulb lights up because the conductor completes, or closes, the circuit and electricity can flow from the ba ery to the light bulb and back to the ba ery! If it doesn't light up, the object is an insulator and it stops the flow of electricity, just like an open circuit does. When you set up the circuit in step 1, it was an open circuit. Electrons could not flow all the way around because two of the wires were not touching. The electrons were interrupted. When you placed an object made of metal between the two wires, the metal closed or completed the circuit — the electrons could flow across the metal object to get from one wire to the next! Objects that completed the circuit made the light bulb light up. Those objects are conductors. They conduct electricity. Most other materials, like plas c, wood, and glass are insulators. An insulator in an open circuit does not complete the circuit, because electrons cannot flow through it! The light bulb did not light up when you put an insulator in between the wires. If you're using wires or alligator clips, take a good look at them. Inside they are made of metal, but they have plas c around the outside. Metal is a good conductor. Plas c is a good insulator. The plas c wrapped around the wire helps keep electrons flowing along the metal wire by blocking them from transferring to other object outside of the wires. Have students chart the conduc vi es to formulate a chart to see insulators and conductors throughout experiment. Homework follow‐up: Go home and find and list 20 insulators and twenty conductors. Bring in one item from your list to test to see if you made a logical guess. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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LIMBS
Materials: 
Conductors and Insulators
Three pieces of insulated electrical wire  Long coil of uninsulated copper wire  Two size D ba eries  Metal paper clips 
Tall drinking glass  Resistor  Metal spoon or screwdriver  Compass Day 4 Introduc on: Discuss magne c fields and provide the students with the defini on. Magne c fields are the por on of space near a magne c body or a current‐carrying body in which the magne c forces due to the body or current can be detected. Student Ac vity: Instruc ons Power Source 
Tape the two ba eries together so that each has a different end facing up. Make sure they are very secure and do not roll, or else you may lose your electrical current. 
Take two of the insulated wires and a ach one to each of the paper clips. One should be a ached on the end to each ba ery. 
Place one of the paper clips across the tops of the two ba eries. If the paper clip does not reach to the center of each ba ery, you may have to unbend it so that it is longer. 
Affix a strip of tape along the paperclip and halfway down each ba ery. Be sure to keep the paper clip in contact with the center of each ba ery and keep the free end of each wire accessible. 
Turn the ba eries over, and do the same to the other side. Again, make sure that this paperclip also makes contact with the center of the ends of the ba eries both before and a er affixing the tape. Electromagnet 
Leave about six inches of copper wire straight, and then start wrapping the rest of your copper wire around the middle of the glass, staying away from the mouth and bo om as you wind. 
A er at least 20 coils around the glass, make sure you have at least six inches of copper wire straight and free at this end of the coil as well. 
Connect one of the wires from the power source to one of the free ends of your copper wire coil. Make sure the copper connects with the metal part of the insulated wire. 
Connect the other wire from the power source to your resistor. The third copper wire will go from the other terminal of the resistor to the other free wire of the copper coil. 
Test the magne c field inside the glass by taking metal objects and placing them inside the glass. They should become magne zed while the current is flowing through the copper coil. Paperclips will s ck together. The metal part of a screwdriver or the spoon s cking out of the glass should be magne zed while the current is on, a rac ng other metal objects to it. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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Conductors and Insulators
Electromagne c Field Try to keep your compass s ll and level on the table. Watch the compass needle as you close and reopen the circuit. Draw what happens in your journal. Homework follow‐up Have students go home and discuss how a magne c field could impact a person’s prosthe c limb. Would it impact them? Founda on Knowledge Energy is power, the ability to do work. Every me anything moves, whether it’s the wind, water, cars, trees, people, clocks, or animals, it is energy that makes it happen. All movement is energy. It takes energy to cook a meal, ride a bicycle, speak to a friend, turn on a computer, or listen to a song. We use energy every day. And just like a car cannot run with an empty fuel tank, we need fuel to have the energy to do out tasks. We gain our energy by consuming food. However, energy comes in different forms, all of which provide the power for an object to do work. Mechanical energy is the energy which is possessed by an object due to its mo on or due to its posi on. Mechanical energy can be in the form of kine c or poten al energy. Kine c energy is the energy which comes from movement, and poten al energy is the stored energy which comes from an object’s placement. A ball flying through the air has mechanical kine c energy due to its mass and the speed of its movement. A ghtly‐wound spring in a windup toy has poten al (stored) energy which will change to kine c energy (movement) when the spring is released. The string of a bow when drawn back to shoot an arrow has mechanical (poten al) energy, and, when released, changes to kine c energy to rapidly push the arrow away from the bow. A fire, a hot cup of coffee, or a hea ng stove has “thermal” or heat energy. Temperature is really a measure of how much thermal energy an object has. The higher the temperature the faster the par cles, or molecules, of an object are moving. A cooking stove heats the air inside the oven and when the cake mixture is placed in the oven, the thermal heat of the air is transferred to the cake and it bakes. A microwave works differently; it uses microwaves (longer waves around a food in length are the ones that help heat food in the microwave itself) to make the par cles inside the food move more rapidly. The resul ng heat from the faster moving par cles cooks the food. Light energy is something we take for granted, but it is becoming even more important than ever. Light is able to travel through space, unlike sound, that needs air or some other medium to be transmi ed. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal LEARNING
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Conductors and Insulators
The por on of the electromagne c spectrum that humans can see is commonly called “light.” Light energy travels in a straight line, but it can be reflected. Light is reflected when it bounces off a shiny surface, such as a mirror. Light can also be refracted, meaning it can be “bent” when it travels from one medium to another. Because light travels slower in water than in air, a pencil placed in a cup of water will appear broken at the point of entry into the water. Curved lenses in telescopes refract light in order to magnify the picture. Advances have been made even recently to u lize light energy beyond just illumina on. Laser lights have become important tools for doctors in surgery, for the manufacture of CD and DVD players and computers, and even for teachers and speakers who use laser pointers in their presenta ons. All ma er is made up of atoms. Electrical energy is created when electrons, small par cles of atoms, are caused to move along a path called a circuit. For the electrons to flow and electricity to be evident, the circuit must be closed, that is to say the path along which electrons are flowing must not be broken, or open, anywhere along the way. When we turn on a light, we are closing an electrical circuit and the lights come on. When we flip the switch off, we open the circuit, and the electricity ceases to flow. Materials through which electrons flow easily, such as copper wire, are called conductors, while materials such as rubber or plas c, which do not allow electrons to flow through them as easily are called insulators. When electricity passes through coils of wire, it can create an electromagne c field. All electric motors in everything from toy cars to powerful fans use electromagne c fields to create their power. When we listen to someone speak, we are doing so because of the effects of sound energy. Sound is created when an object vibrates. The vibra on of the object pushes the air molecules nearby which travel as sound waves to the listener. Our ears are designed to be sensi ve to these waves of sound, which our brain translates back into the voice which we hear. Sound waves can be demonstrated by striking a metal rod and feeling the vibra on of the ringing rod or by simply placing our hand on our throat and speaking. Sound energy requires a medium such as air or water to transmit, which is why sound does not travel in space. Energy can be altered or changed within objects to meet the needs of people. We can change the amount of sound energy in a radio or television to adjust the volume up or down. We can adjust the amount of electrical energy in a light bulb if we want a room to be brighter or dimmer. A television is an example of how energy can be changed to meet our needs. A television is powered by electrical energy, but the TV changes the electrical energy into light energy so we’ll see a picture and to sound energy so we’ll hear the voices. Without sources of energy, the Earth would be a lifeless planet. We have learned how to harness the various forms of energy for our use, and in doing so, we have made our lives more comfortable and enjoyable. Learning for LIMBS Grade 4.1 — Conductors & Insulators © LIMBS Interna onal