Let There be Light Saba Hedayatollahnajafi GK-12 Down to Earth Fellow Arizona State University Grade 9 Key Words: Battery Electricity Energy Transfer Energy Storage Overview In this lesson, the students learn how to use their cognitive abilities to deduce the basic ideas that define the principles that are the basis for operation of batteries. They will use some of the basic household equipment to make their batteries. Objectives: The students will learn: to design a system and use a methodical testing approach to confirm its functionality what electricity is and how it is generated, transferred, and used how a simple chemical battery functions and how it can be used to power a simple electronics device Arizona State Standards Strand 1: Inquiry Process Concept 1: Observations, Questions, and Hypothesis Concept 2: Investigating and Modeling Concept 3: Analysis and Conclusions Concept 4: Communication Strand 5: Physical Science Concept4: Chemical Reactions PO 2. Identify the indicators of chemical change, including formation of a precipitate, evolution of a gas, color change, absorption or release of heat energy PO 3. Represent a chemical reaction by using a balanced equation PO9. Predict the products of a chemical reaction using types of reactions PO12. Compare the nature, behavior, concentration, and strengths of acids and bases PO13. Determine the transfer of electrons in oxidation/reduction reactions. Lesson Plan, Let There be Light, GK-12 1 National Standards Concept A: As a result of their activities in grades 5-8, all students should develop: • Abilities necessary to do scientific inquiry • Understand about scientific inquiry Concept C: As a result of their activities in grades 5-8, all students should develop an understanding of: • Properties and changes of properties in matter • Transfer of energy Materials Let there be light: 1. Fruit Battery - 2 lemons / station - 2 oranges / station - 2 tomatoes / station or 16 fl oz tomato juice /station - 16 fl oz fresh pineapple juice / station - 3 medium to large sized strawberries / station For each fruit station: - 2 wire connectors/station (or 4 5cm pieces of medium-gauge wire stripped at the ends) - 1 low voltage (~1.8min V) LED (or low voltage calculator) / station (Optional) - 3 copper pennies (or 5cm pieces of copper wire) / station - 3 galvanized nails / station - 1 plastic knife / station - Voltmeter(s) - Extra wire 2. Vinegar Battery - 2 20 oz bottles of white vinegar - 3 25 oz beakers or cups / station - 2 wire connectors / station (or 4 5cm pieces of wire stripped at the ends) - 1 low voltage (~1.8min V) LED (or low voltage calculator) / station (Optional) - 3 pennies (or 3 5cm pieces of copper wire) / station - 3 galvanized nails (or 3 5cm pieces of aluminum wire) / station - 1 plastic knife / station - Voltmeter(s) - Extra wire 3. Salt Battery - 20 ml NaCl - ml water - One 100 ml beakers Lesson Plan, Let There be Light, GK-12 2 - 5cm piece of medium-gauge copper wire 5cm piece of aluminum wire) / station 2 wire connectors (or 2 5cm pieces of wire stripped at the ends) voltmeter Lesson Plan Pre-activity (Time: 30 min) Objective: This pre-activity will introduce the students to the concept of energy obtained from electrical forces and how it can be used to, for example, light up a lamp. It is a great tool to introduce the students to the basics of electricity and will provide them with some background knowledge to perform their inquiry activity. Procedure: Have the students watch the video provided in the website or at: http://video.yahoo.com/video/play?p=electricity&toggle=1&cop=mss&ei=UTF 8&b=5&oid=76c92361b43cc2e2&rurl=www.windham.k12.me.us&vdone=http%3A%2F% 2Fvideo.yahoo.com%2Fsearch%2Fvideo%3Fp%3Delectricity%26toggle%3D1%26cop %3Dmss%26ei%3DUTF-8 Before showing the clip, give the sheet containing related questions to the students. The question sheet is attached. Let There Be Light (Time: One block period (2 hrs). Might extend to two periods if needed) Objective: In this inquiry activity the students will have the chance to construct a simple battery and understand how simple electrical devices are powered and function. The students have the opportunity to device methods to create their batteries using simple tools and the background knowledge they attained from the video. Teacher Reference: Useful information for this section can be found in the following website (focus on the last few paragraphs of the webpage): http://home.howstuffworks.com/battery.htm http://hilaroad.com/camp/projects/lemon/vinegar_battery.html http://hilaroad.com/camp/projects/lemon/lemon_battery.html Lesson Plan, Let There be Light, GK-12 3 Useful information regarding the fruits being using in this lab: Fruit Strawberry Orange Lemon Tomato Pineapple Ascorbic Acid Content (mg/100mg fruit) 56.7 53.2 53.0 19.1 15.4 Ascorbic Acid = Vitamin C (C6H8O6) Procedure: - Ask the following questions from the students to get a general idea of their background knowledge o What are some of the properties of metals? (physical: shiny, malleability, etc. chemical: good conductors (donate/accept electrons easily)) o What is electrical current? (movement of electrical charge from atom to atom in a wire, or, the movement of charged ions in a liquid) o How do you measure the electrical activity of a battery? (let the students elaborate then demonstrate using the voltmeter and mention the direct correlation between current and voltage) o How do you think a battery works? (Do not go into detail, just get an idea of what they might know) o What happens when if you put a metallic wire into an electrical outlet? (elaborate on the dangers of electricity and prevention methods) - Brief the students about the objective of this activity. Things they will learn: o Properties of metals (i.e. conductivity, ability to donate/accept different number of electrons) o How is electrical energy produces from chemical reactions o How do batteries work? o What are batteries made of? Lesson Plan, Let There be Light, GK-12 4 - Send the students to the stations o Station 1: Tomato Battery? 2 tomatoes/tomato juice Wires/connectors 1 LED/voltmeter One plastic knife 3 copper wires 3 aluminum wires o Station 2: Lemon Battery? 2 lemons Wires/connectors 1 LED/voltmeter One plastic knife 3 copper wires 3 aluminum wires o Station 3: Orange Battery? 2 oranges Wires/connectors 1 LED/voltmeter One plastic knife 3 copper wires 3 aluminum wires o Station 4: Strawberry Battery? 2-3 strawberries Wires/connectors 1 LED/voltmeter One plastic knife 3-4 copper wires 3-4 aluminum wires o Station 5: Pineapple Battery? 3 cups of pineapple juice (~25 ml each) Wires/connectors 1 LED/voltmeter One plastic knife 3 copper wires 3 aluminum wires o Station 6: Salt Battery? One large cup of slat-water (~20ml salt - 80 ml water) Wires/connectors 1 LED/voltmeter One plastic knife 1 copper wire 1 aluminum wire o Station 7: Vinegar Battery? 3 ~ 25 ml cups filled with vinegar Wires/connectors Lesson Plan, Let There be Light, GK-12 5 1 LED/voltmeter One plastic knife 3 copper wires 3 aluminum wires o Station 8: Vinegar Battery? Power your calculator 3 ~ 25 ml cups filled with vinegar Wires/connectors 1 low V calculator/voltmeter One plastic knife 3copper wires 3 aluminum wires - The extra materials are provided by request - Be sure to mention to student NOT to taste any of the fruits - Each station should also be provided with the worksheet (refer to Appendix) - After all groups successfully lit up their LEDs/calculators (or have measured at least 1.5 volts using the voltmeter), make sure all LEDs/calculators are disconnected - Gather the students from the stations and have them present their ideas for how the battery functions to the class o Why we chose those specific fruits o Why we chose those specific metals o How can we increase the voltage (basics of series connection) - Discuss each idea and explain why they might be right or wrong Evaluation One bases for evaluation is reflections from the discussion. They should also submit their proposed drawn setup to be used for further evaluation purposes. At the end of the session, or during the next session, a quick 10 minute quiz will be given to students to understand their level of understanding regarding the properties of metals and electrical currents. Lesson Plan, Let There be Light, GK-12 6