Hands-on Activity: A Recipe for Air
Educational Standards :
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
Each student needs:
Introduction/Motivation (Return to Contents)
Just imagine... The layer of air around the Earth is only about 10 miles (15 km) thick. This is like the thickness of a human hair placed on a globe that is 45 cm in diameter. Only the bottom 3 miles (5-6 km) of this layer contains enough oxygen for living organisms.
Air is incredible! It is generally invisible (we cannot see or smell it), but we can feel it (wind). It can carry small particles (dust, fog, smoke) and large objects (airplanes, kites, birds, frisbees). It travels all over the planet but does not leave the atmosphere (some of the air you are breathing right now has already been in the lungs of your classmates). See Figure 1, Table 1 and the attached Layers of the Atmosphere Reference Sheet.
The Composition of Air
78% nitrogen (N2)
21% oxygen (O2), needed by most living things
0.9% argon (Ar)
0.1% is a mixture (neon [Ne], helium [He], methane [CH4], krypton [Kr], hydrogen [H2], nitrous oxide [N2O], xenon [Xe] and carbon dioxide [CO2]). Carbon dioxide is a colorless, tasteless and odorless gas, usually present at a concentration of 0.03% of the atmosphere.
Please see Figure 2 or the attached Air Composition Pie Graph Worksheet.
Why Engineers Care
Engineers continually monitor the components of air. It is important for them to know the components of air under normal (or base) conditions so that when they monitor levels of N2, O2, Ar, N2O, CO2 and other gasses, they can tell when the air is no longer at base conditions and may be harmful to humans and the environment. For instance, power plant emissions are always monitored for major deviations beyond that of normal air. In fact, many devices are built into power plants to decrease the levels of carbon dioxide and particulate matter that are released into the atmosphere. Engineers monitor the emissions to make sure these devices are working properly. Increased levels of carbon dioxide and methane, and decreased levels of oxygen are considered dangerous. With these factors in mind, engineers are continually working to monitor and improve the air on our planet.
Procedure (Return to Contents)
Before the Activity
With the Students
Attachments (Return to Contents)
Safety Issues (Return to Contents)
Troubleshooting Tips (Return to Contents)
Assessment (Return to Contents)
Pre-Quiz: Administer the How Much? Pre/Post Quiz. Note that two blank quizzes are provided per sheet (cut them apart). Review students' answers to gauge their base knowledge about the proportions of various gases in air. If students are not very familiar with the gas components and their percentages, tell them they will find out more in this activity. Administer the same quiz at activity end.
Activity Embedded Assessment
Brainstorming: In small groups, have students engage in open discussion. Remind students that in this forum, no idea or suggestion is "silly." All ideas should be respectfully heard. Encourage wild ideas and discourage criticism of ideas. Have students think of something else for which they may be able to use a circle graph (pie chart). Possible ideas include: age/height/weight/gender/eye color of students in class or the number of students in each grade. Then, have students create new charts (with or without M&Ms).
Discussion Question: Ask the students and discuss as a class:
Post-Quiz: At activity end, administer the How Much? Pre/Post Quiz again. Compare students' answers to their pre-quiz answers to gauge their changes in content knowledge.
Activity Extensions (Return to Contents)
Give students a data table expressing the percentage composition of the atmosphere and have them create a graph with their M&Ms that represents the data. Challenge them to make more than one type of graph (bar, circle, etc.).
Research the atmospheric compositions of other planets. Create M&M circle graphs to represent the other atmospheres.
Demonstrate the composition of air with a jar of marbles. Use 10 marbles, 7 of one color (representing nitrogen), 2 a contrasting color (representing oxygen), and 1 a third color (representing argon).
Activity Scaling (Return to Contents)
For younger students in grades 1-2:
For younger students in grades 3-4:
For older students:
Note: This may be confusing to students since they will have 7/10 in the small circle, yet when they make a bigger circle they will have 14/20. Students may incorrectly assume that 7/10 + 7/10 = 14/20. If you try this activity, you may want to use different colors for the big circle so that the browns are associated with 1/10 (seven of them), while the blues (for example) are associated with 1/20 (14 of them).
References (Return to Contents)
EEK! What is ozone? Hole in the ozone layer? Environmental Education for Kids, Wisconsin Department of Natural Resources. Accessed July 19, 2004. http://dnr.wi.gov/org/caer/ce/eek/earth/air/ozonlayr.htm
Gaseous Composition of Dry Air, Table 3.1. ENS 23: The Physical and Chemical Environment, Spring 2005, University of California-Santa Cruz. Accessed September 13, 2006. http://eesc.columbia.edu/courses/ees/slides/climate/table_1.html
Kalman, Bobbie and Janine Schaub. The Air I Breathe. New York, NY: Crabtree Publishing Company, 1993.
ContributorsAmy Kolenbrander, Daria Kotys-Schwartz, Janet Yowell, Natalie Mach, Malinda Schaefer Zarske, Denise W. Carlson
Copyright© 2004 by Regents of the University of Colorado.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder
Acknowledgements (Return to Contents)
The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.