Half Frozen Water?

Our second science lesson went well but was very different from our first lesson! Jumping right into materials management, Jen and I need more on top of it! The ice that we had set aside at the end of last lesson was NOT frozen as it should have been. Luckily, Debi brought extra ice cubes and was thoroughly prepared for her lesson, and for that I thank her! Once we did have ice, we set up the materials table, once ice cube per plastic bag, one data sheet and brand new journal per student, and colored pencils for the time keeping. The teacher had mentioned that the kids get a bit antsy if they sit too long, so to keep in check with their attention spans we decided to start the lesson on the classroom rug. We introduced the lesson by recapping what we had learned during last lesson, what the properties of solids and liquids are and what we put in the freezer for this lesson. Jen made the point that liquids take the shape of the container they are in and that solids can be things like pillows and paper. She tore a piece of paper to show the kids that just because it ripped, doesn't mean it changed from a solid. The ice cube tray we originally had, being half melted, turned into a teachable moment. We asked the kids what they thought would happen vs. what did happen. They were all just as surprised as we were that the ice didn't melt! We talked about the main objective of the lesson: to see what methods work the best for melting an ice cube the fastest. I covered safety talk and how to use senses properly and looking back on it, I could have said a lot more. When we spoke to the teacher after, she mentioned telling the kids exactly what you DON'T want to see happen and that is definitely what I'll be thinking about next time.

The kids were asked to walk back to their seats and row by row retrieved all their supplies. We went over the data sheet, telling them they'd be melting the ice the fastest (without taking it out of the bag) and what they need to record. We talked briefly about telling time and writing down the big and little hand of the clock to mark their start time. The kids then went to town and did whatever they thought would melt the ice. This is where the "what not to do" talk would have been important. Some kids were stomping on the bags and some were putting it under the legs of chairs and desks to break it apart, even hitting it with their pencils and erasers. We walked around and talked to each group, seeing what methods they were using and urging them to write down their data. After all the data was collected, they were asked to clean up their supplies, dump the water, and wipe up any spills that definitely did occur. We gathered them back at the rug and went over the day's work.

During our discussion, the students told us how long it took them to melt the ice (data that we probably could have made into a nice graph) and more importantly what methods they used to melt the ice. Each students at one point said they used their body: hands, back of the neck, heavily breathing on the bag, sitting on the ice, to melt it. From there we asked what is the common theme among these and the students told us that adding heat was why they melted. We determined that the kids who had the ice melted within two or three minutes used the most amount of body heat. This conversation tied into the frameworks for the lesson. Physical Science Standard 3 says to describe how water can be changed from one state to another by adding or taking away heat. The kids definitely understood that the form of water that is ice can be changed back into water by adding heat. The teacher gave them a quick oral pop quiz in order to be certain they understood the concepts. We also brought out the charts of properties from the first lesson and Jen noticed that there was a specific point under the Solids column that said they "can't be ripped." She revisited what had happened when she ripped the paper and the kids understood better that solids can be broken down into smaller solids. 

Overall, the lesson went well because they students learned the information we were presenting. It was difficult to compare to the first which was much more controlled, because we did most of the talking in the first lesson, compared to the students running the show this time. We'll work on transitions, better safety talks, and being more prepared for next lesson!