Experiments With Helium

Deceleration

• You can observe how helium moves more slowly than the air around it by performing a simple experiment. Attach a small helium balloon to the floor of a car using a piece of string, keeping it free to move in any direction. Go to a vacant car lot and drive around, then break quickly. Notice how the helium balloon appears to move toward the rear of the car as you do this. This demonstrates that it does not jerk forward, like an object does, and decelerates more than the surrounding air.

Buoyancy

• Demonstrate that helium is lighter than air. Fill a foil balloon with helium and tie a string to it. Blow a balloon using your lungs and, again, tie a string to it. Blow each balloon to the same size. Observe the difference between the two balloons. Notice that the helium balloon floats, while the other balloon sinks. This experiment shows the difference in weight between air and helium.

Lifting Power

• Assess how much weight helium can lift. Blow up a series of helium balloons, filled to the same volume. Collect a series of small objects varying in weight. Tie one to each of the balloons. Find out how much weight the helium balloon carries before it sinks. Helium is able to lift around 1 gram per liter. Perform a calculation with your measurements to see how accurate your results are.

Density

• Helium is less dense than air, and as a result, affects the sound of your voice when it is inhaled. Test this by inhaling a breath of helium. Speak immediately after you do this, and notice how the pitch of your voice changes. However, helium is poisonous if you ingest too much because it starves you of oxygen. Therefore, only perform this test two or three times on the same day.