Have you ever wondered why hot air goes up and rises? It’s because of something called “convection.”
Imagine you have a balloon filled with hot air. When you let go of the balloon, what happens? It goes up, right? That’s because the hot air inside the balloon is lighter than the cool air around it.
How Hot Air Rises Activity for Kids
My 3-year-old is obsessed with The Magic School Bus series of books. At first, I wasn’t too sure of these books but, wow, are these books effective? My son knows more than me about A LOT of topics thanks to this series.
So I am not embarrassed to admit that I sourced this idea from The Magic School Bus Inside the Hurricane. The activity is so simple, I had to share it with you.
Materials:
- Piece of paper
- Scissors
- Needle & Thread (or tape)
- Lamp
Approach:
- Draw a spiral on the paper
- Cut out the spiral (older children can do these first two steps on their own)
- Put the needle & thread through the top of the spiral (make sure a knot is tied at the end). I actually ended up taping the thread to the spiral.
- Hold the spiral by the thread above the warm/hot light bulb
- Watch the hot air rise and make the paper spiral spin
Science Behind How Hot Air Rises
When the air gets heated up, its molecules move really fast and spread out. This spreading out makes the air lighter. And when something is lighter, it wants to go up. It’s just like when you have a big bunch of balloons and you let them go, they fly up into the sky!
So, when we have something hot, like a fire or a heater, it heats up the air around it. The hot air then starts to rise because it wants to go up and mix with the cooler air. It’s like a little dance between the hot and cold air.
This rising of hot air is called convection. It’s like a big air dance party where the hot air moves up and the cool air moves down. It happens all around us, even though we can’t see it.
Isn’t that amazing? So, the next time you see smoke rising from a fire or feel the warm air from a heater, you’ll know that it’s because hot air likes to rise up and dance with the cool air.
Follow-Up Questions:
- Ask your children to postulate why the spiral spins.
- What does the light bulb do to the air?
- What happens to the warm air? Where does it go?
- What does this activity do to the spiral?
Thanks for visiting!
Marnie