This lesson establishes understanding of the factors required to meet this standard:
MS-PS3-3: Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.* [Clarification Statement: Examples of devices could include an insulated box, a solar cooker, and a Styrofoam cup.] [Assessment Boundary: Assessment does not include calculating the total amount of thermal energy transferred.] Students will model understanding (SEP 2) and explain how Structure and Function (CCC) determine how matter and energy interact.
Heat transfer is too abstract to grasp without the ability to see it with infrared cameras or discussing the phenomena at the subatomic level. The prohibitive price of FLIR cameras would normally prevent most schools from empowering their students to see heat transfer, however, The Concord Consortium site has recorded several infrared experiments that can be used in our classes.
I use one of the infrared videos from the Concord Consortium's 'Infrared Tube' channel to elicit student ideas about the experiment and then encourage my students to explain the phenomenon of thermal conduction. Again, I utilize a KLEWS chart and P.E.O.E. to assist students through their metacognitive understanding and 3-dimensional learning, as well.
In this series of questions, students investigate the questions:
"How does something get hot?"
"Why do metals feel colder?"
"How can our understanding of matter help explain how objects warm up or cool down?" (Crosscutting Concepts)
The idea in this series of lessons is for kids to apply their understanding of density of metals (Crosscutting Concept), experienced in our matter unit to help explain the phenomenon of thermal conduction variability of different metal types. Students investigate various ways to test other types of metals to see if they get the same results. Additionally, students may be curious about insulators, as well. The end result leads to students developing some type of device that maximizes or minimizes thermal energy transfer.
Since this is the first lesson on heat transfer, I want to elicit students ideas about the phenomenon of conduction. I ask several questions and students record their thoughts and pictures in column one of their KLEWS chart. I want to know how students think objects get warm, why metals feel colder than other matter and how our understanding of matter can help explain how objects warm up and cool down. Many students thought that cold things make objects colder. Some students made connections to molecular structure that we developed when studying density, but most were unsure of how matter and energy were related. At the end of this series of lessons, students will reflect on their original thoughts and demonstrate their ability to explain heat transfer at the subatomic level.
I want students to see heat transfer because visual learning is a powerful tool in science classrooms. I either have students watch the video on their computers or I project the video on the board, based on our availability to technology. Predict, Explain, Observe, and Explain (P.E.O.E.) is the strategy that will help students share their preconceptions and then record observations about what actually occurs. They will then have their pre- and post-conceptions and thoughts next to each other so that they and you can see their progress. Use this opportunity to check in with students, especially when their original thoughts are different from their observations. Help students make connections by asking them to talk you through what they've discovered and what they still need to know. Developing this rapport with your students will help establish an inquiry mindset.
I want students to plan and carry out investigations to deepen their understanding about heat transfer, especially with metals. To promote inquiry and student choice, I allow students time to discuss what they want to know about the phenomenon and simply ask them to record their questions in the 'Wondering' column of their KLEWS chart.
Many questions on the KLEWS chart revolved around why metals let heat travel through it faster than foam. Many students knew about insulators and conductors, but lacked details about what makes each material different. My goal was to have students model metals and foam to deepen their understanding of heat transfer in different materials.
Once students develop a "need to know" list and questions to investigate in their KLEWS chart, it is time to allow them to research using computers. They will then try to explain to the best of their ability why metals transfer heat better than foam.
As this is occurring, I circulate around the room probing students about their thoughts. Given the fact that students already studied metals during the density lessons, I want to activate that knowledge and help them make connections between matter and energy interactions (Crosscutting Concepts).
To do so, I ask them to recall what they remember about the molecular structure of metals. If they don't recall that metals are closely packed together, compared to other types of matter like plastics, I ask them to sift through their notebooks to help them remember. When I circle back to that group, I make sure to check for understanding by asking how the molecular structure of metals compare to other matter.
Once students have researched the topic and utilized resources from previous lessons in class, I ask them to visually represent--at the molecular level -- why the metal transfers heat, while the foam doesn't.
This video highlights an example of a student model. It establishes an important misconception to look out for, which is that students think that molecules get bigger when they heat up.