Teaching Heat Transfer – Middle School NGSS

I have been having so much fun teaching heat transfer to my 6th graders!  I am really mixing it up this year since we are transitioning to NGSS standards.  There are so many fun and easy hands on activities to help the kids understand the concepts.  I have been finding that deep level understanding is a challenge for many of my students and this is leading to misconceptions.

I introduced heat transfer with an activity about thermal insulators and conductors (but I didn’t use introduce those words) where students feel and record observations of 3 different materials – wood, styrofoam, and metal (these materials had all been sitting at a constant room temperature).  The metal felt colder than the other two materials, but then, when the measured their temperatures, they were all the same temperature.  This led to some confusion – a great discrepant event.  Many students were stymied and even came to me saying their thermometers didn’t work.  I love baffling my students.  In the final part of the activity, the students put ice on the 3 materials and predicted which would melt the most and then tested the prediction.  It was interesting how many students chose styrofoam because it “felt warmer” even though it was the same temperature as the others.  The rest of the class thought they would all melt the same amount since they were all the same temperature – once again, they were amazed to see that the one on the metal melted the most.  This activity was a great use of discrepant events and phenomena that we could refer to for the rest of our study of heat transfer.

 

The second day we did some notes on heat transfer – using a demonstration to get students thinking about what is going on with the movement of particles and drew heat transfer diagrams showing the direction of thermal energy transfer.  We also reviewed radiation, conduction, and convection.

On the third day I wanted to check their understanding of the concepts so I used this Page Keeley Probe – The mitten problem.  I made a graph of the students results and then we had a great debate in class about which idea was correct.  During this students did a great job using the idea of heat conductor and insulator, but it was clear there were still some misconceptions. Many students thought the mitten thermometer would be warmer since “mittens keep your hands warm” and failed to realize there was no heat source.  Other students had the idea that the “cold would get out of the mitten” even though we had spent time focusing on cold being lower energy, they still thought cold was something that can move.

We did another activity with metal washers to see how the number of hot washers put in cold water affected the temperature of the water.  It was really easy to see that more washers had more thermal energy to transfer to the water.

Finally, the students completed a STEM challenge to design and build an insulated container to keep an ice cube cold.  They got to choose fro ma variety of materials to build their container and then they calculated the %remaining.  It was really interesting to see what materials the groups chose.  A could groups chose to line their container with aluminum foil and they ended up having less remaining than the control (an ice cube without insulation).  When I asked them after why they thought they got these results they realized that foil was a thermal conductor and was not the best choice for their project.