Eliciting Student Ideas: What is Heat? What is Temperature?
Lesson 4 of 11
Objective: SWBAT will be able to describe their initial ideas of what heat energy and temperature are and how they are related to the kinetic movement of molecules.
This starts a series of lessons that introduce students to Heat and Temperature. I teach these in the context of a my unit on Changes in Earth's Atmosphere in order to apply the understanding of heat transfer on atmospheric phenomena as opposed to stand alone physical science lessons.
This set of lessons gets students thinking about how heat is transferred through conduction, convection, and radiation.
You begin with an elicit of student's ideas on heat and temperature followed by engaging them in discussion of their ideas.
First up is a lesson from the American Chemical Society, where students complete an activity in which heat is transferred from hot water to metal washers and then from hot metal washers to water. Students will view a molecular animation to better understand the process of conduction at the molecular level. Students will also draw their own model of the process of conduction.
Next, students observe the reaction rate of Alka-Seltzer tablets dissolving in water of different temperatures to illustrate that the molecules of water and particles of the tablets move faster when water is heated as well as provide a visual example of how heat is the motion of molecules.
A lab modeling the Greenhouse effect looks at heating of soil and water with and without an "atmosphere" as part of an exploration of heat transfer by radiation. I also use this time to discuss the multiple uses of the word radiation.
We end our study of heat transfer by looking at convection and convection currents through a series of mini labs before concluding with a design challenge where students are invited to design and construct an insulating device that will keep 250 ml of water warm for the longest time.
Built into these lessons are activities where students use technology to collect data, learn and apply the science of energy transfer, use math skills in design and construction of a model incorporating STEM principles.
Science and Engineering Practices
Planning and Carrying Out Investigations
Planning and carrying out investigations in 6-8 builds on K-5 experiences and progresses to include investigations that use multiple variables and provide evidence to support explanations or solutions.
- Plan an investigation individually and collaboratively, and in the design: identify independent and dependent variables and controls, what tools are needed to do the gathering, how measurements will be recorded, and how many data are needed to support a claim.
Constructing Explanations and Designing Solutions
Constructing explanations and designing solutions in 6–8 builds on K–5 experiences and progresses to include constructing explanations and designing solutions supported by multiple sources of evidence consistent with scientific ideas, principles, and theories.
Apply scientific ideas or principles to design, construct, and/or test a design of an object, tool, process or system.
Engage in Argument From Evidence
Engaging in argument from evidence in 6–8 builds on K–5 experiences and progresses to constructing a convincing argument that supports or refutes claims for either explanations or solutions about the natural and designed world(s).
- Construct, use, and/or present an oral and written argument supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem.
- Heat is a substance.
- Heat is not energy.
- Temperature is a property of a particular material or object. (Metal is naturally cooler than plastic).
- The temperature of an object depends on its size.
- Heat and cold are different, rather than being opposite ends of a continuum.
- Objects of different temperature that are in contact with each other, or in contact with air at different temperature, do not necessarily move toward the same temperature.
- The kinetic theory does not really explain heat transfer. (It is recited but not believed).
- Objects that readily become warm (conductors of heat) do not readily become cold.
I begin this lesson with an elicit to gain perspective on my students ideas on heat and temperature.
As students enter the room have the following projected or written on the board:
What is heat, what is temperature, and what is the difference?
Spend a few minutes recording* your thoughts and be ready to share.
*TIP: If you are using science journals as part of your course management have students record these questions in their journal.
If you are not using science journals (I strongly encourage you to start!) than have students record their ideas following your directions. An idea would be to have students use a graphic organizer to record their ideas. Writing is "thinking", and it is important to create opportunities for students to write.
I recommend giving students the option to use any graphic organizer of their choosing. As I am teaching this to 8th graders, most had experience using T-charts, Venn Diagrams, lists, etc. To encourage independence and personal style they can select any strategy. If your students needs more guidance, or have not had as much work with graphic organizers I'd suggest picking one to start with and have them all practice.
Monitor the class and bring them back together once all are finished.
Ask students to turn to their neighbors and share their ideas. I like to have students create a mindmap to record their group ideas. This helps to keep the talk "accountable" to the work expectation and engages students simultaneously.
Monitor the group discussion and keep them moving along. If they have questions at this time, try to not give any "right" answers, but encourage them to record their ideas and not worry about being right. Once all the groups have completed their discussion and/or made their posters, bring the class back together and ask each group to share what they discussed.
Here are samples of student mind maps.
While they are sharing, I like to ask clarifying questions and open the floor for some discussion. This isn't the place to debate who "got it right" but instead hear where your students are in their understanding. Encourage a friendly discussion. This embraces the spirit of the practice of engaging in argument from evidence.
By the end have a working definition for both heat and temperature and add these to your science journal indexes (if you are using them). Here is nice resource from the East Bay Educational Collaborative for setting up a student index.
I could on and on about the value of science journalling. It really is an indispensable part of good science teaching. An in depth resource for using journals is Science Notebooks in K-12 Classrooms. In addition Washington State has put out the two resources (listed below), both are very helpful and can be found at sciencenotebooks.org as well.
You will revisit these ideas later and make changes to them as your students build understanding from the activities.