K – 2nd grades
Difficulty of Project
Less than $5.00
Because of possible latex allergies, caution should be taken when using balloons
Readily available or easily purchased at the grocery store
Approximate Time Required to Complete the Project
30 minutes to conduct the investigation and collect the data; one day to prepare the science fair display
To investigate whether air has mass and weight
6 balloons (same size and shape)
7 pieces of string about 8 inches in length
Air is all around us.Because air is mostly invisible, many young children mistakenly assume it has no mass or weight. Air is made up of different gases, including nitrogen, carbon dioxide, water vapor, oxygen, and others. All of these gases are composed of particles, or molecules.
In this investigation, balloons filled with air are compared to show that air does have mass and weight.
Terms, Concepts, and Questions to Start Background Research
mass:the size or amount of something compared to its weight
weight: heaviness; the amount something weighs
inflate: to fill with air
Air has weight and mass.
Does air have weight?
Does air have mass?
What inflates a balloon?
Gather the necessary materials.
To show that air has mass, have an adult help inflate the balloons to six different sizes.
The mass of the air causes the balloons to inflate.
Tie off the end of each balloon and then tie a piece of string to the end of each balloon.
Using the marker, label the balloons A, B, C, D, E, and F.
Predict which balloon is the heaviest. Record your prediction.
Tie one end of a piece of string to the center of the ruler. Tape the other end of the string to a table so that the ruler hangs freely below. Be sure that the ruler balances straight across when it is hanging. Move the string to make adjustments.
Compare the weight of the balloons by tying different combinations of balloons to the ends of the ruler exactly one inch from the end. The balloon that tips the ruler down weighs more than the other balloon. Record the data.
“Air is Matter” at http://www.teacherdomain.org/resource/phy03.sci.phys.descwrld.air
Branley, Franklyn M. Air is All Around You. HarperCollins Children’s Books: New York, 1962.