The actual lesson does not take a lot of time, but the ice cube will need time to melt. When I taught the lesson, it was a very hot day, so we only needed about 20 minutes for the ice cube to melt. You will need to adjust the amount of time you allow for the cube to melt based on the intensity of the sun and temperature in your area.
This lesson begins with an inquiry investigation. The students are going to explore how the sun is a source of heat by melting an ice cube. I purposefully do not build background prior to teaching the lesson, because I want to see what individual students know and also get a feel for any misconceptions my students have. The inquiry style of this lesson also allows the students to make connections to the content that will be taught during the lesson.
I pass out the recording sheets and have the students put their names at the top. I then explain to the students, We are going to do a little investigation involving ice. I will place a bag with an ice cube at your spot. Please don't touch the bag. I want you to use your eyes to look at the ice cube and draw what it looks like on your recording sheet.
I give the students their ice cubes and give them time to draw what it looks like. After everyone has time to complete their drawing, I continue. Boys and girls, this year we have talked a lot about different things that a scientist does. There is a special thing that scientists often do before the begin an investigation or experiment. Does anyone remember what that is called? That's right, they make a prediction. And what is a prediction? (Everyone responds-"a really good guess"). So, we are going to make a prediction. What will happen to our ice cube if we place it in the sun for two hours. Write on the lines what you think will happen.
After everyone is done writing, we move outside to begin the actual investigation.
For this part of the lesson, we move outside. The students are instructed to find a place to put their ice cube that is directly in the sun. I take the extra ice cube and I show the students that I am putting it in a shaded area. I say to the students, You are all putting your ice cube in the sun, but I am going to put mine over here where there is no sunshine.
We then leave the ice cubes. I check on the ice cubes a few times during the investigation. I want to make sure the student cubes have melted, but also that the bag in the shade still has some ice in it. When we have reached this point, I call the students back out to retrieve their bags.
After the students have retrieved their bags, we move back into the classroom. I have the students get out their recording sheets and draw a picture of what the bag with the ice looks like now. After everyone has recorded their results, I show them that the bag with the ice cube that I placed in the sun, still has some ice in it I say to the students, I want you to think about your ice cube and my ice cube. Now, I want you to write down, "why" you think what happened to your cube happened. See work sample.
After they have written their explanations, I invite the students to share their "whys". It is important for the students to be able to articulate their ideas. This also allows time for the students to learn from each other and pick up new vocabulary. The conversation we have is quite interesting. I observed that several of my students had a good understanding of what happened to the cube. I was also surprised by a few misconceptions that the students have (the air in the bag was hot from the classroom and the wind caused it to melt).
During this part of the lesson, students are analyzing their data and using their observations to create an explanation. This engagement in Science and Engineering Practice, Analyzing and Interpreting Data. This analysis help the students to formulate explanations, supporting Science and Engineering Practice 6, Constructing Explanations and Designing Solutions.
To wrap up the lesson, I ask the students to discuss a question with a neighbor that allows them to apply what we learned today in a practical application. I say to the students, I stopped at the store and I picked up an ice tea to take to swimming pool. Where is a good place for me to keep the ice tea so it stays cool? I want you to discuss this with your neighbor. Make sure you tell WHY it would be a good place to keep to the tea.
I give the students time to talk and when everyone has shared with their neighbor, I invite some students to share with the class. I make sure to have them emphasize the "why". It is fun to listen to their reasoning and rational based on our experiment that we did today.