[If you desire you can see the worksheets and initial reflection associated with this lesson here.]
Have you ever watched ice melting? Yes? Well you have experienced the excitement of this lab. Honestly, this lab is not one I would have done, but it is one we do in our school so I felt obligated. That was the first issue with the lab. I was about 2% engaged and invested in it and that was apparent to my students.
The second issue with the worksheet itself. I was just beginning to get used to formatting documents to be done digitally on the iPads and they found the worksheet and how I formatted the questions confusing. Part of that is the questions are sort of squished in with everything else and part of it is that the students didn’t feel like they needed to really read the lab as the instructions seemed so straight forward.
The third issue is the data the students got was horrible. It was probably due to how I had the lab structured, though it didn’t help that a bunch of my groups didn’t have time to get to the boiling stage before the end of the period. Measuring the melting of ice cubes with our thermometers resulted in temperatures beginning around 20*C, eventually dropping to around 5*C, and then slowly and inconsistently rising up to 100*C. I tried changing things throughout the day to improve the data and at the end of class discussed the data they should have gotten and why they were not getting the right data. But, when you are just demonstrating a basic concept the data really needs to show the concept correctly.
So, the activity somewhat failed because of my lack of enthusiasm, the worksheet, and the set up of the lab itself. Though I am not sure my students would have been any more engaged if the data was great.
Now, I say “somewhat failed” because there was part of the lab that went splendidly – my students. By this point they’d written a number of lab conclusions and one main part of those is looking back at the lab and asking what you would do differently if you did it again.
My students suggested:
- Tracking the temperature change when freezing water to see how it compared
- Comparing the temperature change with different amounts of applied heat
- Comparing the weight periodically to see the change to vapor
- Trying to melt different liquids (frozen juice, soda, milk) and seeing how it compared
- Comparing time to melt using hot plates and microwaves
- Seeing how different sizes of ice compared in how they melted
I think those suggestions were awesome. The lesson may have failed, but my students sure didn’t.
Looking towards next year I think I will at least move the ice melting part of the lab to being a video demonstration (on 5x speed) with a better set up that isn’t practical given my number of lab groups throughout the day. I would also like to add a second part to the lab that is a student inquiry into the suggestions above among others. Though, I need to consider if there would be enough time to finish that lab during our class periods.
But all in all I feel like even though this was probably my worst lesson of the year, it is a lesson for me to grow and reflect.