How Much Oxygen Is in the Air?

Grade Levels: 5 - 10

When you step outside and take a big breath of fresh air, do you have any idea what you're breathing in? The atmosphere is made up of a variety of gases, including nitrogen, oxygen, argon, carbon dioxide, neon, helium, methane, and so on. The primary ingredient is nitrogen, followed by oxygen.

You can do your own test of how much oxygen is in the air by making a controlled environment and using a common material to pull the oxygen out of the air. You'll need some of those hand-warmer pouches that outdoorsy types use in the winter. You can find them at sporting goods or hardware stores, and they're generally inexpensive.

The hand warmer pouches contain various materials that are sealed in plastic. When the materials are shaken together and exposed to the air, which occurs when you open the package, they react with one another and begin to oxidize. The oxidation causes heat. Some popular brands of hand warmers are Hot Rods and Heat Factory.

Fasten a pouch to the inside bottom of a tall, straight glass. You can do this with heavy tape. Then invert the glass onto a shallow plate that contains water.

What will happen is that the materials contained within the hand warmer will deplete the oxygen inside the glass. The other stuff-the nitrogen, carbon dioxide, argon, and so forth-will stay in there, and the oxygen will be replaced with water that will rise from the plate. You'll be able to tell how much oxygen was in the glass by the percentage of water it contains after all the oxygen is used up.

The simple science behind this experiment is that the hand warmers function due to a chemical reaction. The pouches contain iron, which, when exposed to oxygen, oxidizes and makes heat. When the iron oxidizes-or rusts-it devours the oxygen in the air. You can mess around with this idea and perhaps come up with an alternative you like better.

The project suggested here, however, is interesting and fairly dramatic without being very difficult to put together.

Excerpted from The Complete Idiot's Guide to Science Fair Projects © 2003 by Nancy K. O'Leary and Susan Shelly. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.

To order this book visit the Idiot's Guide website or call 1-800-253-6476.

Free 7-Day Trial for TeacherVision®

Sign up for a free trial and get access
to our huge library of teaching materials!

Start Trial


Free Gift with Newsletter Sign-Up
Do you receive our free newsletters? We send out seasonal content tie-ins, topical resources, and daily activities. And now when you sign up for any TeacherVision newsletter, we'll send you a packet of our most popular back-to-school essentials as a free gift!

October Calendar of Events
October is full of events that you can incorporate into your standard curriculum. Our Educators' Calendar outlines activities for each event, including: Fire Prevention Week (10/4-10), Metric Week (10/4-10), World Space Week (10/4-10), Earth Science Week (10/11-17), Chemistry Week (10/18-24), Teen Read Week (10/18-24), Make a Difference Day (10/24), and Halloween (10/31). Plus, celebrate Bullying Prevention Month, Diversity Awareness Month, Learning Disabilities Month, and School Safety Month all October long!

Bullying Prevention Month
October is Bullying Prevention Month, and it's a crucial topic for teachers and administrators to address. Bullying can cause both physical and emotional harm, and it can range from inflicting physical abuse to cyber-bullying (the use of cell phones, social networking sites, and other forms of technology to cause emotional distress). Learn how to recognize several forms of bullying and teasing, and discover effective techniques for dealing with and preventing bullying in your classroom.

Happy Halloween! Kids love this holiday and all the spooky decorations, games, and stories that go along with it. (Not to mention the candy, of course!) Take advantage of their enthusiasm with classroom connections and fun activities.