1 TEAK Chemical Reactions & Electricity Lesson Plan Page 1 Overview Chemical Reactions & Electricity Kit This kit contains activities for the students to gain a better understanding about chemical energy and its use in creating electrical energy. Basic concepts of chemical energy including chemical bonds and chemical reactions will be presented. Additional Materials Required Fruit Paper Towels Learning Outcomes How Energy can be Transformed How to Recognize a Chemical Reaction Chemical Energy How Batteries Work Engineering Connection Engineers are always working on ways to improve current technology. One such technology is the battery. Improving rechargeable batteries found in products such as cell phones, laptops, and electric cars by developing ways for them to last longer is important. Also, engineers are working on batteries that are smaller than a human hair that are designed for use in the medical and aerospace industries. Activity Descriptions Fruit Battery Activity- 35 minutes This experiment demonstrates how chemical energy can be transformed into electrical energy, like a battery. Student teams will create their own fruit battery used to run a digital clock and experiment with different kinds of fruit (electrolytes). Partial support for the TEAK Project was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
2 TEAK Chemical Reactions & Electricity Lesson Plan Page 2 NYS STANDARDS Science Elementary Physical Setting Standard 3: Matter is made up of particles whose properties determine the observable characteristics of matter and its reactivity. Students: Observe and describe properties of materials using appropriate tools. Describe chemical and physical changes, including changes in states of matter. Standard 4: Energy exists in many forms, and when these forms change energy is conserved. Students: Describe a variety of forms of energy (e.g., heat, chemical, light) and the changes that occur in objects when they interact with those forms of energy. Observe the way one form of energy can be transformed into another form of energy present in common situations (e.g., mechanical to heat energy, mechanical to electrical energy, chemical to heat energy).
3 TEAK Chemical Reactions & Electricity Lesson Plan Page 3 Resources NMSEA Curriculum Listing From Oil Wells to Solar Cells Running Oil Live Green Go Yellow Enviro Literacy Teacher s References Environmental Literacy Council Timeline of Energy History Renewable Energy Lesson Plans Energy Changes Makes Things Happen EIA Energy Kid s Page Frequently-Asked Questions about fruit batteries MadSci Network Comment [mbb1]: Use APA or MPA styles for formatting websites, see for an example. Formatted: Font: (Default) Calibri, Kern at 14 pt Science with Dr. T. TeachEngineering Resources for K-12 Note: Many of these resources were used in assisting the creation of the following lessons plans and we want to thank and reference them for their valuable instruction. Formatted: Font: (Default) Calibri, Italic, No
4 TEAK Chemical Reactions & Electricity Lesson Plan Page 4 Chemical Reactions & Electricity (Approximately 1 hour) Concepts covered: How Energy Can Be Transformed How to Recognize a Chemical Reaction Chemical Energy How Batteries Work
5 TEAK Chemical Reactions & Electricity Lesson Plan Page 5 Group discussion: Chemical Energy (Pose the following questions to the group and let discussion flow naturally try to give positive feedback to each child that contributes to the conversation) **Note: If they have already done Molecules and Fuel Cell Technology, use this page as review. ** Can you help me think of some forms of energy? Kinetic Potential Electrical Chemical Mechanical Heat / Thermal Electromagnetic Nuclear What happens to energy when we use it? Energy is neither created nor destroyed. The total amount of energy stays the same it only changes from one form to another. Look around. Everything you see has something in common. What do you think it is? Everything is made up of matter and energy. Atoms are the smallest particle of matter. The subatomic particles atoms are made up of are just tiny pieces of energy. Do you know what an electron is? It is the negatively charged subatomic particle that is found in a cloud around the center of an atom. How do atoms combine? Atoms combine by sharing or lending electrons. This is called a chemical bond. What is Chemical Energy? It is the energy stored in the bonds of atoms and molecules. A chemical reaction takes place when these bonds are broken or formed which releases the stored energy. What are some ways you can tell a chemical reaction is occurring? Gives off heat instant heat pack Becomes colder instant cold pack A gas is produced baking soda & vinegar A solid is produced - rust There is a color change Light is produced glow stick Where is chemical energy found in your life? Batteries chemical to electrical Gasoline chemical to mechanical/kinetic Digestion chemical to thermal/kinetic Burning chemical to thermal/light Rust chemical reaction: substance
6 TEAK Chemical Reactions & Electricity Lesson Plan Page 6 But how does a battery relate to chemical energy? Batteries are used to store chemical energy. When a battery is used, it is an example of converting chemical energy into electrical energy. Have you ever wondered how a battery works or what s inside one? There are two metal plates or posts called electrodes which react with the acid in the battery. This results in a chemical reaction that produces electrons. When the two electrodes are connected by a wire, the electrons are able to move through it. This movement of electrons is known as electricity. Have you ever seen the little number on a battery that has the letter V next to it? Do you know what the V stands for? Volts You can find out the number of volts a battery produces by using a multimeter, which you ll do today Did you know when you mix zinc with the acid found in fruit, a chemical reaction occurs? A very small amount of hydrogen gas is produced. The acid found in fruit actually reacts with several kinds of metals. Using this knowledge, you are going to create your own battery out of fruit.
7 TEAK Chemical Reactions & Electricity Lesson Plan Page 7 Fruit Battery Activity Objectives Student should become aware that energy can be found in unexpected places. Students should learn the value of teamwork when doing experiments and finding solutions. Materials for Each Group Procedure 5 different pieces of fruit (Lemon, Lime, Kiwi, Grapefruit, Orange, Potato ) 7 Alligator Clips 1 Multi-meter 1 Clock Assembly 7 Copper Nails (positive charge) 7 Zinc Nails (negative charge) Paper Towels Pass out a kit and an activity handout to each group. Tell them not to open the kit. Read through the Challenge 1 questions on the top of the handout with the students. As a group, have them decide what they think and write down their answers on the lines for hypothesis. Go over what they re responses are. Explain that the copper nail is the positive side of the battery and the zinc nail is the negative side of the battery. Tell the students that the kinds of fruit will be tested in the activities. o It may be helpful to write down that copper=positive and zinc=negative on the board. Instruct the students that the activities are going to be done step by step, and that all students should raise their hands when their group is done with a step. o The instructor should walk around to each group while they are working and make sure that they have set up the activity/are using the multimeter correctly. It s important that the copper nail is connected to the positive side of the alarm clock. ALL - CE - TE - DE - Open the kit and take out the bag of engineering roles. Place them face down on the desk. (Can also be done by facilitator.) Each student should take a role tag and read what their engineering job will be. Take out a piece of fruit, a zinc nail, and a copper nail. Put the nails into the fruit. Make sure that they are almost all the way in, but leave room for attaching wires to them. Take out the multimeter, test probes, and laminated multimeter card. Make sure that the leads are in the position shown on the card. Turn the dial to the 20V position. Place the red end of the multimeter on the copper nail and the black end on the zinc nail. Read the voltage off the multimeter display screen. **Remind the test engineers to hold the test probes by the plastic and not the metal ends. Record the type of fruit and the voltage produced in the chart on the activity handout. The CE, TE, and DE should repeat the previous 3 steps for the other 4 pieces of fruit. DE - Have all the DEs pair up to compare voltage data. They should record the data from the other teams in the second table on the handout.
8 TEAK Chemical Reactions & Electricity Lesson Plan Page 8 ALL - Answer the questions on the bottom of the handout. After everyone is finished, go over the questions/answers with the class. Have the students flip their handout over. Read the Challenge 2 question on the top of the handout with the students. As a group, have them decide what they think and write down their answer on the line for hypothesis. Go over what they re responses are. EE - Take out 2 test leads and attach one to each wire coming out of the clock. Now attach the clip on the red wire to the copper nail and the clip on the black wire to the zinc nail. Did the clock light? EE - DE - EE - TE - DE - ALL - EE - CE - ALL - If the clock didn t light, keep adding fruit until it does. Use the diagrams on the handout to help you connect the fruit correctly. Once the clock lights, stop adding fruit. In the table on the handout, write down the types of fruit used to light the clock in column 1. Then use the voltages you measured from Challenge 1 to fill out column 2. Add up the voltages. Disconnect the clock from the nails. Place the test probes of the multimeter on the nails where the clock was attached. Read the voltage off the multimeter display screen. Record the voltage on the activity handout under actual voltage. Answer the questions on the bottom of the handout. After everyone is finished, go over the questions/answers with the class. Unhook all wires from the fruit battery and put them back in the kit. Remove all nails from the fruit and put away. Make sure all parts are back in the kit container and hand the container to the instructor. Expected Results The students should figure out that different kinds of fruit produce different voltages. They should find that it takes several pieces of fruit to start the clock and then determine fruit would not be a good alternative to batteries. If groups try to set an alarm, it will not work. Explain that the alarm relies on current as well as voltage coming from the fruit, and the fruit can t produce enough power to light. Activity Extenders Have the students form the largest chain of fruit they can. Attach the multimeter so they can measure the total voltage and/or current. End of Fruit Battery Activity
9 TEAK Chemical Reactions & Electricity Lesson Plan Page 9 CHALLENGE 1: Fruit Energy Observation: Zinc will chemically react with acid found in fruit (producing hydrogen gas). Questions: Can a battery be created using fruit, zinc and copper? Does the kind of fruit matter? If it does, which kind of fruit would work the best? What is your hypothesis? (What is your best guess?) Test your hypothesis: Place one zinc nail and one copper nail in a piece of fruit. To test if there are any volts being produced, place the red end of the multimeter on the copper nail and the black end on the zinc nail. Type of Fruit Voltage (V) Analyze the Results: Have one person from your group collect data from at least one other group. Then compare the results. Type of Fruit Voltage (V) Group 1 Voltage (V) Group 2 Voltage (V) Group 3 Voltage (V) Group 4 Voltage (V) Group 5 1. Chemical energy is being stored in the fruit. 2. Which fruit produced the most voltage overall? Will be whatever they measured 3. Did the same type of fruit always produce the same amount of voltage? Yes or No 4. What do you think could cause the same type of fruit to produce different amounts of voltage? How far the nails are pushed in, how juicy the fruit is, has one been squeezed? 5. Can you think of any other kinds of fruit that would work? Pretty much any kind of fruit will work, however the more acidic the fruit the better it works
10 TEAK Chemical Reactions & Electricity Lesson Plan Page 10 CHALLENGE 2: Fruit Battery Observation: Fruit can be used to store chemical energy like a battery. Question: Can a fruit battery also be used to convert the stored chemical energy into electrical energy? What is your hypothesis? (What is your best guess?) Test your hypothesis: If fruit is going to be used as a battery, it needs to have a positive and negative side just like a normal battery. The copper nail is the positive (+) end and the zinc nail is the negative (-) end. Start by connecting one fruit to the clock to see if it lights. Keep adding one more fruit until it lights. Use the following diagrams as a guide. ***When connecting the fruit to the clock, the copper nail must be connected to the red wire and the zinc nail must be connected to the black wire*** More testing: Check to see how many volts it took to start the clock. Add the individual voltages for each fruit you used from what you found in Challenge 1. Now test the actual voltage by connecting the multimeter instead of the clock in the above diagrams. Experiment with other fruit combinations if you have time. Type of fruit used to light the clock Estimated Voltage Measured Voltage from Challenge 1 Analyze the Results: + + Actual Voltage Total = Do they match? Yes No 1. Chemical energy is being converted into Electrical energy. 2. How many pieces of fruit did you use to start the clock? Will be whatever they used 3. How many volts did it take to start the clock? ~ 1.5V 4. Did more than one combination of fruit start the clock? Will be whatever they tested 5. Do you think a fruit battery is a good alternative for a regular battery? See Concluding Discussion
11 TEAK Chemical Reactions & Electricity Lesson Plan Page 11 Concluding Discussion: Chemical Energy (Pick and choose depending on student questions/responses to activity) Is a fruit battery a good alternative for batteries? Not really. Each piece of fruit only produces a very small voltage. They also produce an extremely small current that will not work in most applications. To replace even a small battery you need several pieces of fruit which takes up a lot of space. If you tried to set the alarm during the activity, you would have noticed the fruit did not produce enough power for it to go off. The fruit also rots. Ewww. What does a fruit battery have to do with engineering? Engineers are researching how to improve batteries. They are trying to make the rechargeable batteries we use in things like cell phones, laptops, and electric cars last longer. They are also working on extremely small batteries (smaller than the width of a human hair) that can be used in the medical and aerospace industries. Engineers need to know the properties of materials they are working with. If you were an engineer designing and building a fruit juice processing facility, you really would not want to use any materials that are going to react to the fruit s acid. What other types of fruit/food do you think would work in this activity? Lemon, Lime, Kiwi, Grapefruit, and/or Potato What difficulties did you have constructing the fruit battery?
12 TEAK Chemical Reactions & Electricity Lesson Plan Page 12 Further Exploration (More advanced questions) Why do you think the fruit battery works? Zinc is an active metal and will react readily with acid found in fruit. A transfer of electrons takes place between the zinc and acid. o The zinc is oxidized (loss of an electron) and the acid is reduced (gain of an electron) to hydrogen gas. o This happens whether or not a copper nail is present. The copper nail helps draw power from the fruit and channel electrons through an external circuit. What is the difference between zinc and copper that allows the fruit battery to work? Because of its atomic structure Zinc wants to give away 2 electrons and the copper wants to gain an extra electron. This imbalance creates electron flow, which creates electricity.
13 TEAK Chemical Reactions & Electricity Lesson Plan Page 13 Trouble-Shooting Guide Fruit Battery Activity Problem: Unable to light the alarm clock. Solution: Check that enough voltage is being generated by the circuit (~1.5 V) using the multimeter. Try putting the zinc and copper nails closer to one another. Ensure the copper nail is attached to the (+) red wire and the zinc nail is attached to the black (-) negative wire. Try pushing zinc and copper nails into the flesh of the fruit, as opposed to the rind. Try adding one more piece of fruit and/or squeezing the fruit. Try moving the wires coming from the clock around. Try a different clock assembly. Problem: Unable to produce more than 0.5 V Solution: Ensure the pieces of fruit are connected in series. Ensure that each zinc nail is connected to a copper nail.