EarthLabs for Educators > Climate and the Carbon Cycle > Lab 1: Living in a Carbon World

Lab 1: Living in a Carbon World

The lab activity described here was created by Candace Dunlap of TERC for the EarthLabs project.

Summary and Learning Objectives

In Part A, students trace the pathway of carbon from the atmosphere into trees where carbon can be stored for hundreds to thousands of years. In Part B, students go outdoors and measure the amount of carbon in a local tree. In Part C, students use molecular model kits and Jmol images to explore how carbon compounds are built and how they are transformed into new carbon compounds as the move through the carbon cycle. In Part D, students learn about combustion, a carbon cycle process that burns fossil fuels. Students analyze graphs and videos to determine if the human activity of burning fossil fuels is changing the chemical composition of the atmosphere.

After completing this investigation, students will be able to:

  • explain why carbon atoms can form the basis of millions of different types of carbon compound molecules;
  • describe how the carbon atoms in CO2 absorbed via plant photosynthesis provide the carbon atoms for all of the new carbon compounds a plant produces;
  • explain how carbon compounds are transformed in four processes that are critical to the carbon cycle: photosynthesis, cell respiration, biosynthesis and combustion;
  • apply skills to measure the amount of carbon in a tree;
  • explain how combustion moves the carbon atoms in fossil fuel hydrocarbons into the atmosphere.
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Activity Overview and Teaching Materials

Detailed overview of what students will do in each lab activity, how long it will take, and what materials are required to complete the lab.

Research by Michigan State indicates that students have a very limited understanding of how the global carbon cycle works. See What Carbon Cycle? College Students Lack Scientific Literacy, Study Finds Specifically, this research indicates that students do not understand the processes that transform carbon compounds nor do they understand that most of a tree's growth comes from atmospheric CO2 and water. Lab 1 is designed to address these misconceptions and lack of understanding of basic carbon cycle processes that underpin the carbon cycle.


NOTE: Some sections in Lab 1 are easily adaptable for flipped lessons.

In Part A: Students view a TedEd video to consider the question, "Where does a tree get its biomass?" They analyze images to trace the pathways of carbon between trees, soil and the atmosphere. Time estimate: 1 class period.

In Part B: Students go into the field to measure the carbon stored in a local tree. They use allometry to calculate the mass of carbon stored in their local tree.

For each group:
  • A local, nearby tree - preferably having a circumference of 38cm (15 inches) or more.
  • A regular flexible tape measure that will fit around the circumference of the tree; or a diameter tape measure; and/or a long string, marker and push pin
  • Tree identification guide and/or tablet APP such as Leafsnap
  • Calculator/pencil/paper NOTE: Calculators with exponents capability are required.
  • A table of the Allometric Coefficients for Common North American Trees. (Microsoft Word 2007 (.docx) 88kB Jan7 15)
  • Student Data Sheet (Microsoft Word 2007 (.docx) 71kB Oct13 15)
For the class:
  • Access to a spreadsheet program such as Microsoft Excel and Apple's Numbers
  • (Optional) Soil testing kits and meters for testing NPK(fertilizer), soil moisture, soil pH,
  • A regular flexible tape measure that will fit around the circumference of the tree; or a diameter tape measure; and/or a long string, marker and push pin. Note: for larger trees, the string, marker and push pin may be best.

Time estimate: 2 class periods.

In Part C: Students carry out 4 investigations to learn how carbon compounds can be transformed into new, different carbon compounds.

In Part C Investigation 1, students look for evidence of a chemical change when they bubble CO2 from their own breath into limewater (calcium hydroxide) producing two new compounds: calcium carbonate and water. For the class: NOTE: This first part is done as a class demo. However, the entire investigation can be done as a DEMO.

  • piece of chalk
  • white vinegar
  • eyedropper
For each group:
  • clear plastic cup partially filled with limewater
  • clear plastic cup partially filled with water
  • empty clear plastic cup
  • two drinking straws
  • small (#2) coffee filter
  • water
  • white vinegar
  • eyedropper
In Part C Investigations 2 and 3, students use molecular model kits to model photosynthesis, respiration and biosynthesis of large, complex biomolecules built from multiple glucose molecules.

For the class:

  • Ball and stick molecular model kit(s) that contain carbon atoms, hydrogen atoms, oxygen atoms and bonds. You can purchase One Mega Molecule kit for Photosynthesis and Cellular Respiration from http://www.megamoleculesllc.com/biology.html or from Amazon.com. Alternatively, a "Molecules of Life" kit may be purchased through any major science catalog such as Carolina Biological. You will need 6 carbon atoms, 12 hydrogen atoms, 18 oxygen atoms and 36 bonds to build 6 carbon dioxide molecules and 6 water molecules needed for each group. NOTE: Based on the number of students in your class and the size of the groups, you may need to order a second kit.

For each group of 2-4 students:
  • A plastic baggie that contains 6 CO2 molecules and 6 H2O molecules
In Part C, Investigation 4, students investigate what types of elements (atoms) carbon compounds can be made of by analyzing JMOL images of several plant-produced carbon compounds. This introduces students to the role of soil nutrients (nitrogen, phosphorus, sulfur, magnesium and iron etc) in building carbon compounds.
Each student will need:
  • Paper or lab notebook to create their CHNOPS chart;
  • Jmol color coding chart. This chart is embedded in the Part C student pages;
For the class (Optional):
The following interactive Jmol biomolecule visualization Apps for IPAD/IPHONE allow students to rotate, zoom-in and find background information on biomolecules:
Time estimate: 2 class periods


In Part D, students use videos, graphs and interactives to explore the combustion of fossil fuels and increased fossil fuel emissions to the atmosphere since the beginning of the Industrial Revolution. Students analyze graphs and videos to determine if the human activity of burning fossil fuels is changing the chemical composition of the atmosphere.
Time estimate: 1-2 class periods

Printable Materials

Download and print files needed for each lab activity, including images, data tables, and Stop and Think questions.

To download one of the PDF or Word files below, right-click (control-click on a Mac) the link and choose "Save File As" or "Save Link As."

Teaching Notes and Tips

General recommendations for classroom implementation as well as guidelines and facilitation tips for leading class discussions.

General Recommendations:

  • If unfamiliar with a hands-on activity in this Lab, consider a practice run before implementation.
  • Print out any paper-based materials before starting the lab.
  • Have students keep a lab notebook or journal to record important notes, questions, data and findings.

In Part A:

To save time, you may want to assign the first part of Part A as part of a FLIPPED lesson.

In Part B:

In Lab 1B,

Gather materials for the tree carbon activity. You may want to go out to the area where students will be selecting and identifying trees and identify those trees that are on the Allometric Coefficients for Common North American Trees. (Microsoft Word 2007 (.docx) 98kB Feb23 15) table and flag them. Discuss with students the value of future classes collecting carbon data on the same trees.

In Part C:

Time is always an issue so you may want to do the CO2 and lime water experiment as a demo. Dealing with all of the atoms and bonds creates management issues, especially if you are doing this activity with more than one class. You will need to develop a management system that works for you keeping in mind that incoming students should have a baggie ready for them with six pre-made CO2 and H2O molecules.

In Part D:

To save time, you may want to FLIP the first part of this lesson. Then, you can have students do the graph and analysis activiy "Are Humans Changing the Chemistry of the Atmosphere" together in class.

Student Notebooks

If you have your students keep a lab notebook and/or a journal, here are some suggestions:

Suggestions for how to use Student Notebooks for Lab 1:

  • Have students write down the learning objectives for Lab 1.
  • Have students record answers to all Stop and Think questions.
  • Have students record answers to Discussion questions.
  • Have students record diagrams they have drawn when prompted by
  • Have students record important hands-on lab activity components. This could include research questions, data, observations, drawing, graphs, and conclusions.

Assessment

There are several options for assessment of student understanding of material introduced in this lab. Choose from the following list, or create your own assessments.

There are several options for assessment of student understanding of material introduced in this lab. Choose from the following list, or create your own assessments.

Assessment Options:

  1. Assess student understanding of topics addressed in this investigation by grading their written responses to the Stop and Think questions or by using Stop and Think questions as part of whole-class or small group discussions.
  2. Written Test for Lab 1


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    Test key


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Science Standards

Lab 1 supports the following Next Generation Science Standards (NGSS):

Science and Engineering Practices
4. Analyzing and interpreting data
5. Using mathematics and computational thinking
7. Engaging in argument from evidence

Disciplinary Core Ideas
HS.ESS2.D: Weather and Climate
HS.ESS3.A: Natural Resources
HS. ESS3.B: Natural Hazards
HS.ESS3.C: Human Impacts on Earth Systems

Cross-Cutting Concepts
2. Cause and effect
7. Stability and change

Examples of how students engage with the standards:


Go to Next Generation Science Standards (NGSS)

Additional Resources

Explore background information and content extensions related to Lab 1.

Background information