Script: Hello apprentice engineers! Yesterday you learned about electrical circuits and a little bit about how they work. As we prepare for the Ingenia Light Up Parade, you’ll be using your electrical engineering skills to create a light up hat.
Can someone tell me something about electrical circuits that they learned yesterday?…. If you remember, we talked about the power source, switches and circuit. We also talked a little bit about conductive materials. Does anyone remember what it means if a material is conductive? …. Conductive materials are materials that allow electricity to flow through them. The material's ability to conduct electricity is known as conductivity. Electric currents can flow easily through materials with high conductivity and very poorly through materials with low conductivity. You’ll need to use what you’ve learned as you prepare for the Ingenia Light Up! parade.
Today, we will be testing different materials to see if they have high conductivity or low conductivity. The moisture on our skin is a high conductivity material. To demonstrate how the moisture in our skin has high conductivity, I have an energy ball that has a battery, light, siren and wires connecting the metals that we see on the outside. We are going to create a circuit. To do so, I want you all to stand up and form a circle. In my hand, I have an energy ball. I want you to hold hands with the person on the left and the right of you.
Hold hands with the student to your left and hold the energy ball with your right hand. Ask the student on your right to touch one of the metal elements on the ball with their finger while you touch the other metal element with your finger. The energy ball will light up and make a noise. Ask one pair of students to let go of each other. The ball will turn off. Ask them to hold hands again. The ball should light up again. Ask the student who is touching the metal element to touch the white plastic part of the ball instead, without touching the metal. The ball should turn off. You can pass the ball around so each student gets to experiment touching the ball to see it light up and off. Students should be excited with many ideas and questions in their minds.
Script: Now that we have created our own circuit, I want you to go back to your chairs and think about how the energy ball is working.
Tell students that as apprentice engineers, it is important to understand how circuits work and what are the best materials to use when working with electricity.
Ask students:
Refrain from calling on students to give their answers. Ask them to draw a model to explain their ideas. Students will draw a model of what they think is happening to light up the energy ball. They should also write down any questions they have in the question area or on the board. Their models might include circuits and explanations that electricity is being conducted through the hands of people.
Distribute Open Circuit Template pdf
Script: You all had great ideas on how the circuit worked. If you remember, I stated that inside the ball there is a battery, light, siren and wires connecting each metal electrode that you see on the outside. When both or one of the sensors are not touched, there is no complete path for the current to flow. This is called an open circuit and is why the ball didn’t light up or make a sound. When both sensors are touched and we are fully connected, it creates a complete path for the current flow, in this case, through our hands. When the circuit is complete with no gaps, it is called a closed circuit. Since there was a complete path with no gaps, the ball lit up and made a sound. We made a closed circuit when we placed one finger on each metal electrode. The small electrons traveled from one electrode through our fingers to the other electrode which completed the circuit. When the circuit was complete, it lit up and the siren made a sound.
NOTE: For your reference for a video explanation, see this video but you don’t need to play it for the students. https://www.youtube.com/watch?v=Ro2tpyeh0Ck&t=113s (www.youtube.com/@scionthefly)
Script: Now that we have played around with open and closed circuits, we will be creating an open paper circuit using a template.
Pass out the open circuit template, conductive tape, masking tape, one LED, one battery and scissors.
Script: The conductive tape or copper tape is going to be our conductive material which will allow the electrons to flow from the battery to the LED. The battery that you all have is 3 volts so they will have enough power to light the LED. To create the open circuit, use the template and follow what the diagram is showing. First you want to put the copper tape along the light brown lines to create the path. Make sure you leave a gap, when you see a gap on the paper. Next you are going to put down the LED making sure you are putting the positive leg on the positive tape and the negative leg on the negative tape. Remember that the longer leg is positive and the shorter leg is negative. The last thing you will put is the battery. One side of the battery is positive and the other side is negative. Just look at the battery to see which side is positive and attach it in the correct orientation.
More instructions on the circuit
To watch a video guide on how to create this open switch, watch this video. You can also play for the students so they can see what they need to do. https://www.youtube.com/watch?v=rO3voO-UUdk (www.youtube.com/@NationalAITC)
Script: To review, the path of a circuit has to end where it started with no gaps. This is called a closed circuit. If there is a gap, the electrons can’t continue so the circuit is broken. This is called an open circuit. In the circuit you just created, when we leave it with the gap, it is an open circuit. The moment we connect the gap by having the copper tape touch each other, it is a closed circuit.
Distribute Lesson 2 Conductivity Worksheet
Ask students to think which materials can close the circuit, which material will allow electricity to flow. Provide them with a bag of materials that would include the following items: a popsicle stick, a plastic straw, a paper clip, a pom pom, a piece of string or yarn, and a piece of foil. Students should discuss in their group and predict which of the materials they think will conduct the electricity and close the circuit and which one will not. They write down their predictions on a chart like the one below:
Provide students with a chart to fill out the data they collect:
As students work on the experiment, you can monitor and ask them some reflection questions such as:
If there is extra time, students can look around the room to test out other materials that are not on the list to see if they are conductive or not. If they have a coin of some kind, they can test that out.
Students should discuss in groups their results and explain what they learned. Then, meet as a whole group so each group can report their results and their conclusions to the large group. Ultimately, they should come to the conclusion that the materials that got the lights to turn on, are conductive and the materials that left the lights off, are not conductive so they don’t allow electrons to flow through. Also, what do they notice about the materials they are made of?
Script: Based on what we have concluded on conductivity, we are going to watch a video that experiments with other materials to test to see if they are conductive or not. As you go through the video, pause at each instance to have them guess if the material is a conductor or insulator.
Show the following video to get more information about conductors and insulators: https://www.youtube.com/watch?v=Y66PW1nIea0&t=78s (www.youtube.com/@funsciencedemos)
Script: We learned that conductors allow electricity to flow through and insulators don’t allow electricity to flow through so they don’t conduct electricity. Now that we know that insulators are things that don’t allow electrons to flow through, what are some of the materials from our experiment that would be an insulator?
Show students an extension cord and ask them:
This is to have them connect why it is important that some things are conductive and other things are insulators.
Ask students to reflect and discuss in their groups:
Ask students to go back to the model they drew with the explanation about the magic energy ball and revise it with any new information they learned today. Go back to the questions they posted at the beginning and check to see if they were answered with the activities and videos.
Closed Circuit: the path of a circuit that has to end where it started with no gaps
Open Circuit: when there is a gap in a circuit and electrons can’t flow through so the circuit is broken
Conductors: materials that allows electricity to flow through
Insulators: materials that does not allow electricity to flow through
Students can think of other materials they would like to test to find out if they are good conductors of electricity. They should make a list of other possible materials to test and design an experiment. They don’t have to conduct the experiment, just think of a way they could test other materials.
