The Lightbulb Just Went On!
Lesson 4 of 11
Objective: Students discover how electricity can be converted to light energy.
I want to immediately engage my students in the thought process about electricity. I knew I could have just given them the materials and taught them directly how to hook up the cables and make the bulb light up and then instruct them on the details of a closed circuit. NGSS creates opportunity for us to abandon that practice and move our students to discovering knowledge, rather than just being told. I am so happy about that because I knew my students learn so much more from the play, experimenting and being immersed in figuring out how the light bulb will light! Being truly with them instead of in front of them also allows a level of connection to my students that elevates the value of the learning to higher levels.
I begin by using What is Electricity SB File, opening it up to the first page to get their minds wrapped around, "What is electricity?" Their answers vary from examples of lights to lightning. As they list the answers to the questions in their notebooks and personally have a chance to think about electricity a little bit more, I start to outline a KLEWS chart (What do I know? What am I learning? What is my evidence? What am I wondering about?, and finally, What is the science behind it?) on the whiteboard. We work through page 3 of the SB file. I list the "Driving Question" on the whiteboard from the SB page so that it is continually in view. We continue discussing each item and making sure that the vocabulary is listed in the "S" column of the KLEWS chart. Students work in their notebooks to copy the information, but I avoid discussing the meaning of the vocabulary because I want them to discover the meaning of those words through their experience.
I encourage them to write down anything they wondered about in the "W" column. I tell them that what they will learn about electricity today will help them understand exactly how electricity works.
Turning Them Loose
As I re-read the "Driving Question" that is on page 3 of the SB file, I challenge kids to prove it! The Driving Question is the key to focusing the lesson. I lay out batteries, black and red cables and small incandescent bulbs around the room along with a pile of blank paper for sketching. I turn the SB file to page 4 and told them that they needed to gather their materials and get going! I remind them that they needed to sketch their plan first on the white sheet. This sheet was the team sheet.
If it didn't work, they would need to sketch another idea and try again. We were exercising our engineering practices through imagining, planning, drawing and then, creating and trying it out. As students hunkered down with their partners around the room, some on the floor and some at their desks, they were immediately engaged and busy. I could hardly get a word in edgewise to ask questions. I roved around as hands shot up to tell me they got the light to light. Then, I started to ask questions. They were pushing questions to get them to think harder. I didn't want it to be easy. Lighting the bulb is not enough. One student began explaining the left hand rule without knowing it. While I didn't teach the rules of the direction that the electricity flows, she completely could see it. I push her by asking why you couldn't just touch the bulb to the battery and make it work.
I also caught a team having a difficult time. I stopped to ask, "What's the problem?" and sit right down on the floor. I start by questioning what they were trying and what they knew already. I began helping the struggle along with gentle suggestions. They are able to finally get the light lighted and are so happy! One pair approaches me because they want to share how they proved their plan. The level of energy and excitement was so wonderful!
As I continue throughout this portion of our lesson to wander and listen to what my students understand, I start to hear words that are listed on the board as vocabulary, used properly. "It flows" is used, and even "pulses" is tried as a word to explain. Several teams think that the flow is from both ends to the light. I correct this misconception when I show the closed circuit illustration on the SB file. They can discover if their experience and thinking is correct at that point. A great explanation happens just before we stop and I am so pleased to see how they clarify their thinking through me pushing them with questions. At first, I thought they thought the energy came from the lightbulb, but they explain. I can feel that it is time to close and remind them to finish filling out their notebooks.
To wrap it all up, it is essential that students have a chance to really share and talk about the experience. I am also looking to see if people could summarize what a closed circuit was and how they are able to prove that energy transfers from place to place. I had encouraged them to take photos of their work just prior to the discussion to help them look at it once again so they could respond to the questions I would be presenting.
I learned... is how they start each of their sharing statements. They talk about open circuits and closed circuits and share that they understand the flow of the electricity and what didn't work. I learned so much from their learning and sharing because just turning them loose with these tools was new for me!
Finally, I ask the question that was the heart of the matter. "Did we answer our Driving Question?" I am so delightfully pleased to hear them explain how we did, presenting the evidence as they precisely explained that yes, we did prove that energy transfers from place to place!
Their exit ticket today is to show their understanding by writing a "quick write explanation " that demonstrates that they understand that electrical energy transfers from place to place.