Lesson Plan. About Electricity. Essential Learnings. Teacher Preparation

Transcription

1 About Electricity Lesson Plan Essential Learnings Lesson Objectives: By the end of this lesson, students should be able to: Define electricity Understand the role of electrons in electricity Know that electricity can be stored Demonstrate the build-up of electrons in the form of static electricity Explain how electrical energy can be transformed into light, heat, sound and motion. Lesson Essential Questions: What is electricity? What is the role of electrons in electricity? How can charged particles be contained? What are some examples of how electricity is transformed into light, heat, sound and motion? Key Vocabulary: battery, electric, electron, energy, negative charge, particle, positive charge, static electricity, stored energy, electricity Teacher Preparation Background for the Teacher Electricity is the flow of charged particles through a conductor. Electricity refers to the flow of energy, and is considered a secondary energy source. This means that electricity comes from the conversion of a primary source of energy, like the sun, fossil fuels, or nuclear energy. These primary sources can be either renewable or nonrenewable, but electricity itself is neither renewable nor non-renewable. The United States produces more electricity than any other country in the world, which means we also use many primary sources of energy. Residential users are the biggest consumers, using about 36 percent of total energy produced. The next biggest group of consumers is commercial use, which uses about 32 percent of total energy produced. The word electricity was coined in the year 1600 by the scientist William Gilbert. Gilbert observed natural electric forces in nature and wrote about objects becoming electrified. Benjamin Franklin performed one of the most famous experiments with electricity when he tied a key to a kite during a thunderstorm and proved that lightning is a form of static electricity. The first electric battery was invented in 1800 by the Italian Alessandro Volta. It is from his name that we get the words volt and voltage. This lesson explores electricity in the forms of static and stored charges. Static electricity is simply the build-up of electrons on an object. They are then transferred whenever that object comes into contact with something else, or they are released in the form of a spark, where they literally jump from one object to another. Stored energy typically refers to batteries. Batteries use chemicals to produce electrons that can be transferred to other objects, thus providing them with energy. Common Misconceptions Be aware that students may have the following misconceptions about electricity: They may think that electricity is produced in a wall socket. In fact, electricity is produced in a power plant. The power can come from a variety of sources, including coal, wind, or hydropower. This electricity is then distributed through power lines that eventually make their way into homes. They might think that objects become positively charged because their electrons have been destroyed. In fact, charge is simply transferred from one object to another in the charging process; it is neither created nor destroyed. About Electricity Page 1 3i Education

2 They may think batteries contain electricity. In reality, the copper wires supply Teacher the flowing Guide electrons through copper atoms. The electrons were there before the battery was connected. In effect, the copper wires are prefilled with a liquid electricity. Prior Knowledge for Students Students will have some background knowledge about electricity, as many of their toys run on electricity. They will know that some appliances and machines can be turned on and off, and that things can run out of stored power. They likely will not have much knowledge about where this power comes from or how electricity is created. It would be helpful in this lesson to call on students experiences with different forms of energy, such as toys that run on small batteries or appliances that must be plugged into a wall socket. In addition, you may find it helpful to review the Fun-damental Electricity & Magnetismwith your students to learn more about some basic ideas of electricity. Materials to Prepare Teacher Demonstration Materials: 4-5 household electrical objects that produce sound, light, heat or motion Computer station with projection device Teacher Demonstration Materials: Computer station with projection device Student Materials: For each student or pair of students: balloon small, lightweight objects such as: o styrene peanuts o paper hole punches from a hole puncher o salt o pepper Computer access Writing paper or science notebook for recording ideas Notes to Teacher: As students complete the Hands-on Activity, they will use the small, lightweight objects to demonstrate the attraction between opposite charges (positive and negative). If students brainstorm other objects and they are readily available, let them use those objects as well. Keep in mind that some students may need assistance with their balloons. You may want to blow up a few balloons ahead of time to expedite the balloon-tying process. Estimated Time for Preparation: ten minutes About Electricity Page 2 3i Education

3 Teacher Guide Session 1 ENGAGE (10 minutes) Stimulate Interest Display a few everyday objects that use electricity to make sound, light, heat, or motion. Examples of possible display objects include an electric toothbrush, lamp, blender, hair dryer, etc. Ask students if heat, light, sound, motion or a combination is being produced by the electricity for each object. Next, show students the video segment Electricity in the Real World. This short video shows examples of the many ways we use electricity. Students may not have ever thought about where we get the electricity that we use so often in our lives, and this video provides a good introduction to get them thinking. After the video, create a KWL chart by asking, What things do you see in this classroom that use electricity? Also ask, What else do you know about electricity? This chart can be referred back to and amended throughout the lessons. These questions will get them observing electricity and thinking about energy. Activate Prior Knowledge Next, ask students, What is electricity? They may know that it is what is needed to turn things on and off, but they may not know that it is a form of energy caused by the flow of electrons through matter. At this point in the lesson they do not need to know this, but by asking the above question, you will gain an idea about their preexisting knowledge of electricity. You may want to ask additional questions, such as, Where does it come from? What is an electrical charge? Add this information to the KWL chart. Do not worry about correcting wrong answers, but do tell students that they should look for the answers to these questions and more throughout the lesson. Finally, post the Essential Questions that constitute what students will be learning. Students may read them or you may wish to read them aloud together. What is electricity? What is the role of electrons in electricity? How can charged particles be contained? What are some examples of how electricity is transformed into light, heat, sound and motion? Inquiry Tip: Students are more likely to be engaged in the rest of the lesson if they are investigating a question they have devised. If students are able to come up with a related question whose investigation will lead to an understanding of electricity and charged particles, allow them the use the Explore to answer it instead.. EXPLORE (Guided Inquiry: 45 minutes; or Directed Inquiry: 35 minutes or more) Exploration Student Resources for Guided Inquiry Reading Passages All Charged Up (Level Three; explanation of electricity) Electrophorus electricus (Level Four; electric eels and batteries as stored energy) Video Segments Electrons (3:01; grade-level-appropriate explanation of atoms and electrons) How Do We Create Electricity? Batteries (2:02; stop at 1:05 to learn how batteries store electricity) Balloons on the Wall (1:05; opposite charges attract, this video helps build student knowledge) About Electricity Page 3 3i Education

4 Glossary Terms battery electric electron energy negative charge particle positive charge static electricity stored energy Teacher Guide Directed Inquiry and Guided Inquiry are two alternate instructional pathways through Explore. For Directed Inquiry, the specific digital resources that students will explore and the order in which students will explore them are specified for the instructor. In this option, you might choose to present the specified resources to the entire class, or you may choose to have students individually explore each resource as you introduce it. For Guided Inquiry, students are given a list of resources to explore on their own. Your choice between the two should be made based on your students level of familiarity with Guided Inquiry as a process and their need for teacher assistance, as well as on such practical matters as the number of computers in your classroom. Note that the time estimates in this lesson are based on Directed Inquiry; a Guided Inquiry session may take longer for students to complete. Essential Question(s): What is electricity? What is the role of electrons in electricity? How can charged particles be contained? Guided Inquiry Have students respond to the Essential Questions by exploring the 3i resources listed in Explore section. Ideally, each student will use more than one resource for information, but no student is expected to use all of the resources within the time allotted. Encourage students to use the Essential Questions as organizers to take notes as they explore. If your students have never before performed a Guided Inquiry using the 3i, you will likely need to lead them through the process of selecting appropriate resources, reviewing them, and taking notes. It is appropriate to use a think aloud to model this process for them yourself to demonstrate how to gather the information. Repeat the Essential Questions that they will be answering for this lesson, and ask students what kinds of resources will likely help them answer these questions and learn about electricity and how electrons flow through matter. For example, you might suggest starting with the video segment Electrons because that seems to be an important idea and is probably a good starting point. Next, you might point to glossary terms and mention that that term is mentioned again. Exploring the glossary term electron and other related terms (i.e., electric, energy, negative charge) might be a good next step for learning more about electricity. Model this process to the entire class for at least a few resources. Encourage students to proceed through the resources in this way. If needed, you may want to further guide students by asking more specific questions: What are other forms of energy? Why is electricity so important in our lives? What s another term for a charged particle? Can electricity flow through all matter? What makes electricity flow better though certain types of objects? What is static electricity? Circulate among the students as they are exploring and challenge them to summarize for you what they have learned. Encourage students to use reading, viewing, and note-taking strategies to get the most out of each resource. About Electricity Page 4 3i Education

5 Directed Inquiry Teacher Guide To begin, provide students with the reading passages All Charged Up and Electrophorus Electricus. You may have all students read both passages, or you may want to divide the class into reading groups and have each group read one passage. If so, use your knowledge of students reading ability to help you form the reading groups. Have students read the passages and record the main points in their notes (main points: 1) electricity is the movement of electrons, 2) electrons are tiny negatively charged particles, 3) electricity is a form of energy, 4) moving electrons can cause other things to move such as a fan, 4) some objects store electrons such as an eel or a battery). After they have finished reading and taking notes, have the students perform a think-pair-share activity. One partner should take two minutes to share their answers to the Essential Questions. The second partner should then take two minutes to share their answers to the Essential Questions. Have the partners then take one minute to solidify their answers to the questions. Select partners to share their answers with the class. Add any new information to the KWL chart. After this activity, students should already have a fairly complete answer to all of the Essential Questions. Next, have students watch the video segments Electrons and How Do We Create Electricity? Batteries. These two video segments also answer the Essential Questions, but do so in a way that provides visual learners a chance to connect to the material. Instruct students to use the Essential Questions to take notes as they view the videos. Their knowledge of electrons will come in handy as they complete the Hands-on Activity later in the lesson. Give the students an example of a concept map. Have students create a concept map that demonstrates the relationship between electrons, electricity, energy, and stored energy. Finally, with any remaining class time, have students spend time exploring the interactive glossary terms battery,electric, electron, energy, negative charge, particle, positive charge, static electricity, and stored energy. These terms can fill in any gaps or confusions students might be experiencing, and can also help them do a self-check of their comprehension. After giving students time to explore the terms, have them pair with a partner and informally quiz each other on the meaning of the terms. Make sure students add to their concept charts where appropriate. After students are finished with the glossary terms, review their knowledge of the relationships among the terms. Have students correct or modify their concept charts as necessary. Also have students add any pertinent information to their notes. Session 2 EXPLAIN (45 minutes) Once students have thoroughly explored the resources and successfully answered the Essential Questions about electricity, instruct them to complete the Exploration About Electricity. This Exploration covers all of the Essential Questions and has students examine both static and stored charges. It is important for students to know the difference between the two, so ask them questions as they complete the student worksheet, such as, How does a battery release its electricity and how does it differ from the ways in which static electricity is released? They should know that the static charge is released when it comes in contact with a positive charge. If the positively charged object is also a good conductor, a spark may be created. A battery stores the electrons to be used later, when it comes in contact with a positively charged conductor. Be sure to summarize the main points from the lesson at this time. The main points include: 1) electricity is the movement of electrons, 2) electrons are tiny negatively charged particles, 3) electricity is a form of energy, 4) moving electrons can cause other things to move such as a fan, 5) there are two forms of electricity: static and stored. Try to dig deeper with your students; get them thinking about real-life examples of electricity and how it works. When discussing the first Essential Question, ask students to brainstorm other forms of energy. They should be able to identify sources of energy such as the sun, hydropower, or fossil fuels like coal or natural gas. When discussing the second question, ask them to describe atoms and how protons are different from electrons. And when discussing the third question, ask them to describe the difference between static and stored charges. About Electricity Page 5 3i Education

6 Challenge them to try to explain how a battery works (a chemical reaction inside the battery Teacher produces Guide electrons). Have students add any pertinent information to their notes. Hands-on Activity Students will complete the Hands-On Activity Creating Static. Sessions 3 and 4 ELABORATE (90 minutes) Virtual Lab: Racing RC Cars (Level One) Virtual Labs, in addition to being an inquiry instructional tool, can be used to assess students skills in science investigation. For this concept, the Virtual Lab Racing RC Cars is particularly appropriate because students can relate their knowledge of electricity to motion. Before assigning the lab to students, however, you may need to model the appropriate process. The Teacher Guide for this lab will help you achieve this. Level One is the most applicable level for this lesson. Level Two likely has too many variables for most elementary levels, and starts to stray from the sub-concepts of this lesson. Before beginning, have students speculate what their results could be. For example, how might a large battery perform differently from a small battery? Ask the same question for motor size. Get students thinking about what stored energy means, and relate it back to the Essential Questions for this lesson. Have them use the Student s Guide Level 1 to plan their investigation before starting. A Student Record Sheet is included with this guide that students should use to record their data once they begin the investigation. Have students take some time to evaluate their data from the Virtual Lab. You may want to ask students questions to help them analyze their results, for example: How did changing the size of the battery affect how fast the car could go? Did all cars with big motors go more quickly than all cars with small motors? How did changing the size of the motor affect how far a car could travel? Students should share their results with a partner, and work together to come to some general conclusions. Check for student understanding by discussing student conclusions as a class. Session 5 ELABORATE (45 minutes or more) Have students complete the Hands On Activity: Make It Light. Project Ideas : To help your students apply their understanding of electricity, you may wish to have them complete some or all of the following projects. The time required to complete each project will vary; some may require students to work outside the classroom. Have students keep a journal of the way they use electricity in their lives. They should record both batteries and electrical currents from wall sockets. Instruct them to write a paragraph describing the importance of electricity in their lives. Have students conduct simple experiments to determine if everyday objects are conductors or insulators of electricity. To do this, you will need breadboards for students to build circuits on, a battery, a small light bulb, wires with clips, and washers to hold the wires in place. If you or your students have never built simple circuits with breadboards, you should conduct a bit of research before proceeding so that you can provide students with a detailed explanation of setting up a circuit. Once students have successfully built a circuit, encourage them to test a variety of materials to see what will make the light bulb light up. After testing many different objects, encourage students to make generalizations about conductors and insulators. Have students write up their results in a short report. About Electricity Page 6 3i Education

7 Instruct students to conduct research on historical electricity experiments, such Teacher as Ben Franklin s Guide key experiment or the invention of the light bulb. Students present their findings in a poster to display in the class. Challenge students to include ways their assigned experiment impacts our lives today. Have students explore scientists who discovered some of the important characteristics and uses of electricity. Some good resources are: Edison: The Wizard of Menlo Park, Introduction: The Discovery of Electromagnetism, Understanding the Connection of Electricity and Magnetism, Benjamin Franklin: The Years of Experimentation, and Ben Franklin: Go Fly a Kite. Students may also search the Discovery Education site for other resources. EVALUATE (20 minutes) Have students complete the Brief Constructed Response (BCR) item titled About Electricity. You may also wish to assign the online concept assessment and use the results in the student reports to guide you in assigning any remediation to students. Review Sheet: Students may review the information in this section using the About Electricity Review Sheet. About Electricity Page 7 3i Education