Some Like it Hot!
Hook students with an example everyone can relate to - themselves! Use the video found on the National Geographic Education website, "U.S. Cold Snap: What Do Bitter Temperatures Do to the Human Body?" to encourage students to think about why and how people stay warm in cold weather.
- Discuss different ways in which humans maintain body temperature. Conclude the discussion by introducing the problem - We are taking a trip to a cold climate. Create a low-cost handwarmer that is small and efficient. Discuss and come to consensus on the criteria and constraints. For example,
- It should be no larger than 10 X 15 centimeters.
- It should reach a temperature of at least 40 degrees Celsius.
- It should maintain that temperature for at least 5 minutes.
- It should cost no more than $2.00. (If you wish to develop a price list for materials)
Investigate the phases/state of matter by examining the relationship of heat and temperature and the resulting molecular motion Background information can be provided in a number of ways depending on the grade level and prior knowledge of students.
Simulations: Molecular Workbench: "Heat and Temperature," activities 1-5 (linked above) are simulations in which students explore heat and temperature, kinetic energy and changing temperature. Only works on computers/laptops.
Simulation: Phet "States of Matter Basics" is a simulation that provides background information on molecular motion in each state of matter. It is written in HTML 5 so can be used on iPads and/or Chromebooks as well as laptops. Downloadable teacher directions and student sheets are available on the site.
Alternatively, the ExploreLearning Gizmo, "Phase Changes," can be used to explore the same concepts. The Teacher Guide and Student Pages are available on the website.
Once students have learned about or reviewed the states of matter and phase changes and how they are affected by temperature, introduce the Bozeman Science video, "Endothermic and Exothermic Reactions." Depending on the grade level of students, you may wish to explain the energy that is released when bonds are formed in a chemical reaction is greater than the energy that was released when the bonds in the original reactants were broken.
Students develop a plan to create their own handwarmer. First they are provided with science background about how handwarmers work from the HowStuffWorks site.
Then, in groups, students brainstorm how to create their own handwarmer. They record their ideas on a shared Google doc. Depending on the grade level you are working with, you may wish to inform students what materials they will have to work with or let them explore a wide range of possibilities that they find in their research.
Students should develop a plan for creating and testing a handwarmer. The goal is to use the optimal amount of materials to develop an efficient handwarmer within the design constraints. Allow students to develop the constraints and criteria and could include cost, size, efficiency, etc. Students can document their work using a design cycle such as:
- Define the problem
You may make this as open or directed as appropriate. Students can plan their initial tests and determine the amounts of each chemical they will use and the size of their handwarmer. They should include what tests they will perform and the qualitative and/or quantitative data they will record.
To have students create the handwarmers - Gather the necessary materials for the class.
The directions linked above are for a reusable handwarmer. This is for teacher use. Depending on the grade level and design experience of your students, you may wish to let them explore the amount and ratio of chemicals they will use. They should follow their written plan, test each iteration, and record their data in their shared Google doc.
Students evaluate their handwarmers . Once they have explored the optimal amount and combination of chemicals, they test each iteration, and record the qualitative/quantitative data in their shared Google doc. Additionally, they will design a vinyl pouch for the chemicals. You may wish to have them decorate the pouch using colored permanent markers or sewing or gluing a cloth envelope for the vinyl pouch. The decoration can be assessed using art design criteria and standards, making it a STEAM activity rather than a STEM activity.
Presenting their design to the public is essential for feedback and comparison of designs. Students have a choice of tech tools they may use to present the handwarmer. In their presentation, students detail the design process and share the data they collected.
As a class, students develop a process to determine how well the handwarmers meet the design criteria and constraints. They compare the designs and evaluate each one.
Higher level students can prioritize the criteria and decide upon tradeoffs. For example, they may decide a larger warmer is OK if it stays warmer longer. Older/more advanced students can evaluate the handwarmers for cost, safety, reliability, and aesthetics, as well as possible environmental impacts.
Key Standards Supported
Speaking & Listening
|SL.6: Presentation of Knowledge and Ideas|
|SL.6.4||Present claims and findings, sequencing ideas logically and using pertinent descriptions, facts, and details to accentuate main ideas or themes; use appropriate eye contact, adequate volume, and clear pronunciation.|
|SL.6.5||Include multimedia components (e.g., graphics, images, music, sound) and visual displays in presentations to clarify information.|
|SL.7: Presentation of Knowledge and Ideas|
|SL.7.4||Present claims and findings, emphasizing salient points in a focused, coherent manner with pertinent descriptions, facts, details, and examples; use appropriate eye contact, adequate volume, and clear pronunciation.|
|SL.7.5||Include multimedia components and visual displays in presentations to clarify claims and findings and emphasize salient points.|
|SL.8: Presentation of Knowledge and Ideas|
|SL.8.4||Present claims and findings, emphasizing salient points in a focused, coherent manner with relevant evidence, sound valid reasoning, and well-chosen details; use appropriate eye contact, adequate volume, and clear pronunciation.|
|SL.8.5||Integrate multimedia and visual displays into presentations to clarify information, strengthen claims and evidence, and add interest.|
|SL.9-10: Presentation of Knowledge and Ideas|
|SL.9-10.4||Present information, findings, and supporting evidence clearly, concisely, and logically such that listeners can follow the line of reasoning and the organization, development, substance, and style are appropriate to purpose, audience, and task.|
|SL.9-10.5||Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest.|
|SL.11-12: Presentation of Knowledge and Ideas|
|SL.11-12.4||Present information, findings, and supporting evidence, conveying a clear and distinct perspective, such that listeners can follow the line of reasoning, alternative or opposing perspectives are addressed, and the organization, development, substance, and style are appropriate to purpose, audience, and a range of formal and informal tasks.|
|SL.11-12.5||Make strategic use of digital media (e.g., textual, graphical, audio, visual, and interactive elements) in presentations to enhance understanding of findings, reasoning, and evidence and to add interest.|
Key Standards Supported
|HS-ETS1-1||Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.|
|HS-ETS1-2||Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.|
|HS-ETS1-3||Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts.|
|MS-ETS1-1||Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.|
|MS-ETS1-2||Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.|
|MS-ETS1-3||Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.|
|MS-ETS1-4||Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.|
Matter and Its Interactions
|HS-PS1-4||Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.|
|MS-PS1-2||Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.|
|MS-PS1-4||Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.|
|MS-PS1-6||Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes.|