I will begin this lesson by having the students transition to the carpet. I will remind the students that we have been talking about observable properties and how different processes effect them. We will review the different processes of heating, cooling, mixing, and dissolving. I will show them a plastic fork. I will ask the students which process would cause the observable properties of the fork to change the most. I will allow time for the students to discuss their thoughts with an elbow partner. Students will share their thinking, and I will inform the students that heat will cause the most changes to the fork.
Next, I will ask the students, "How can we measure the changes and how much heat is necessary to cause the changes in the observable properties of the fork? How will we know how much heat is needed to change the properties and how can we measure the heat?"
I will introduce the vocabulary word- thermometer. We will discuss what we already know about thermometers. Next, I will engage students in viewing the video resource, Early Thermometers.
After the video, I will lead a discussion about how scientists and engineers today use thermometers to measure heat using Celsius or centigrade. I will ask students why do they believe that scientists use the Celsius scale? I will also ask students to think about why it is important to use only one scale. Students will share their ideas.
I will inform the students that today we will be using thermometers. I will provide the students the opportunity to predict at what temperature they will observe ice change when exposed to room temperature.
I will allow students to work in pairs. Each pair will receive a thermometer, a spoon, and a 9 oz clear cup filled with several ice cubes that I froze in ice trays the previous day. Students will also receive the, "What Do You Call an Old Snowman" resource. I will instruct the students to place the ice cube in the cup of ice to note the initial temperature and time on their worksheet. As students are recording their data, I will observe the students and ask the students how does ice change as it is heated? I will ask the students at what temperature do they believe they will observe a change in the ice? I will prompt them to record their predictions on the back of the worksheet.
As students work, I will ask probing questions such as, "How will you know that the ice has changed? What criteria should you use to justify your observations? What evidence will you collect?" I will allow students to use the remaining time to collect their data by using the thermometers and recording measurements of the observational changes as the ice melts inside the cup. I will remind the students to record data at regular intervals, such as every three minutes.
The lesson will conclude with a class discussion after the ice has completely melted. Once students have recorded all of their data, I will ask the students to share their information and what they believed caused the ice to change. I will ask them to explain where they believe the heat energy was coming from that melted the ice. I will ask the class, "Did everyone observe the same effects? What variables might cause a difference in someone else's observations?" We will discuss different variables such as the number of ice cubes, the size of the ice cubes, the position of the thermometer in the cup, and the location of the cup in the classroom.