Why Do Some Molecules Absorb Infrared Energy?
The Lawrence Hall of Science, The Lawrence Hall of Science
Activity takes about one to two 45-minute lesson periods.Learn more about Teaching Climate Literacy and Energy Awareness»
See how this Activity supports the Next Generation Science Standards»
Middle School: 5 Disciplinary Core Ideas, 2 Cross Cutting Concepts, 4 Science and Engineering Practices
High School: 1 Disciplinary Core Idea, 1 Cross Cutting Concept, 1 Science and Engineering Practice
Notes From Our Reviewers
The CLEAN collection is hand-picked and rigorously reviewed for scientific accuracy and classroom effectiveness.
Read what our review team had to say about this resource below or learn more about
how CLEAN reviews teaching materials
Teaching Tips | Science | Pedagogy |
- Educator should definitely include the reading in the surrounding chapter (chapter 2 of the GSS curriculum on Climate Change http://www.globalsystemsscience.org/studentbooks/cc/ch2 about what resonant frequency has to do with why greenhouses gases are able to absorb infrared light.
- This animation http://scied.ucar.edu/molecular-vibration-modes provides a visual representation of molecular resonance and would be useful to use as a reference/resource in this activity .
- Free teacher guide with downloadable files and additional activities is available upon request at: http://www.globalsystemsscience.org/teacherguides.
About the Science
- The activity demonstrates how gas molecules in the atmosphere resonate when they are struck by vibrating photons of light energy. Molecular resonance is a key factor in the ability of greenhouse gases to absorb infrared energy.
- Comments from expert scientist: Addresses a very common knowledge gap in understanding the greenhouse effect, what greenhouse gas molecules do, and which molecules are (and are not) greenhouse gases. The models highlight key structural differences between the non-greenhouse gases (N2 and O2) and the greenhouse gases (CO2 and CH4). It may be helpful to have a link to the “GSS Teacher Guide for Climate Change Chapter 2," which is mentioned as a resource.
About the Pedagogy
- A hands-on activity for students to model how and why greenhouse gases absorb infrared energy and thus warm the atmosphere. Students build simple models of atmospheric gases and compare their resonant frequencies.
- This activity is one of several in a chapter entitled "What's So Special About Carbon Dioxide", in the Climate Change section of the Global Systems Science online curriculum. Teacher Guides for this curriculum are available on a Teacher Site that is accessible by contacting the developer, Alan Gould, at http://www.globalsystemsscience.org/teacherguides.
- A basic understanding of the electromagnetic spectrum, and where wavelengths of infrared and visible light energy fall on the spectrum, is useful.
Technical Details/Ease of Use
- Activity is user-friendly with limited cost for reusable materials. Minimal preparation time required; educator is advised to pre-set the attachment points on the atoms (polystyrene balls) for the bonds (cable ties or pipe cleaners).
- Many different kinds of materials can be used to create models of molecules, but not all of them will allow user to experiment with resonance.