As simple as that scientific experimentDemonstration and demonstration are a great way to show children what happens to gases when they are heated.
The air around us is an example of a gas. Gas particles can move freely in any direction. Gases do not have a fixed shape but rather fill the space they have.
When a bottle with a balloon on top is placed in hot water, the air inside heats up. Hot air particles move faster and with more energy than colder air particles, increasing the volume of the air and inflating the balloon.
Experiment with hot air and cold balloons.
You will need to
An empty 500 ml plastic bottle.
A balloon
two bowls
Hot water and cold water.
Instructions
Carefully place the balloon over the opening of the bottle. Check for holes. The balloon must be airtight.
Carefully fill one container halfway with cold water and the other with hot water.
Place the bottle in the container of hot water and watch the balloon fill with air.
Transfer the bottle to the bowl of cold water and watch the balloon deflate.
Research ideas
Experiment with different water temperatures and record how long it takes the balloon to inflate at each temperature. For this to be a fair test, you will need to make sure the air inside the bottle is at room temperature before placing it in each container of water.
Do your research to find out how long it takes for the balloon to deflate after being in water with different temperatures for the same amount of time.
Why does the balloon explode?
Placing the balloon over the top of the bottle traps the air inside. When the bottle is placed in hot water, the air inside becomes warm. Hot air molecules move faster than colder air molecules. The warmer, faster-moving air expands and enters the balloon, inflating it. The volume of air in the bottle increases as it warms.
As the air cools, the air molecules begin to move more slowly and closer together. This means they take up less space, the volume decreases and the balloon deflates.
Curious facts about the air
The air we breathe contains approximately 78% nitrogen, 21% oxygen and 1% other gases such as carbon dioxide, argon, neon and methane.
Humidity is the amount of water the air can hold before it rains.
air pressure is pressure is the pressure of the air pushing down on the Earth's surface.
The air around us also carries small particles of dust, pollen and pollutants from car exhaust and other sources.
We need air to breathe!
Last updated on March 19, 2024 by Emma Vanstone
