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Using balloons and bubbles to see how gas takes up space.
Have you ever wondered why a balloon gets bigger and bigger when you blow into it, even though you can't see what you are putting inside?
Everything around us is made of matter. Some things are hard like a toy (solids), and some things are runny like water (liquids). But there is a third kind called gas! Air is a gas. Even though you usually cannot see it, it is everywhere. When you blow into a balloon, you are catching gas from your lungs and trapping it inside the rubber skin. The gas pushes against the sides of the balloon, making it grow inch, then inches, and even bigger!
Quick Check
What is the name of the invisible stuff we trap inside a balloon?
Answer
Gas (or Air)
A block is always a square, and a ball is always a circle. But gas is a shape-shifter! Gas does not have a shape of its own. It takes the shape of whatever it is inside. If you blow gas into a heart-shaped balloon, the gas becomes a heart. If you blow it into a long, skinny balloon, the gas becomes long and skinny. It spreads out to fill every single corner of its container.
1. Imagine you have a round bubble wand. 2. You blow air into it. 3. The gas fills the bubble and makes a round shape. 4. Now imagine a square bubble wand. The gas will try to fill that square shape too!
Quick Check
If you put gas into a square box, what shape will the gas be?
Answer
The gas will be the shape of a square.
Gas isn't just for balloons; it can move things too! When gas moves outside, we call it wind. Because gas is made of tiny pieces of matter, it can push against objects. This is how a kite stays up in the sky or how a sailboat moves across the water. The moving gas hits the fabric of the sail or the kite and gives it a big push!
1. Blow up a balloon but do not tie it. 2. Hold the end shut with your fingers. 3. Let go! 4. The gas rushes out so fast that it pushes the balloon across the room like a rocket.
Imagine a giant boat that weighs pounds. Even though gas is invisible and light, if there is enough wind, that moving gas can push the giant boat all the way across the ocean!
What happens to gas when you put it in a new container?
What do we call gas when it moves outside and pushes kites?
Even though we cannot see air, it is still matter that takes up space.
Review Tomorrow
Tomorrow, look around your house and try to find three things that have gas trapped inside them (Hint: check the kitchen or your toy box!).
Practice Activity
Go outside with a piece of paper. Hold it up and see if the moving gas (wind) can push it out of your hand!