Step-by-step tutorial
Step 1
Have a grownup cut the bottle in half. The edge of the bottle can be sharp, so be careful!
Step 2
Tie a knot in the end of one balloon and cut off the top.
Step 3
Stretch the balloon over the end of the bottle and secure with a rubber band. Don't worry if your bottle squishes a bit, it'll still work!
Step 4
Slide a straw into the other balloon and secure with a rubber band.
Test it out! Blow in the straw and make sure the balloon inflates. If it doesn't, your rubber band might be too tight or too loose.Step 5
Push the balloon into the bottle. Press the modeling clay around the straw to hold it in place and seal the opening.
Test it out! Blow one more time and adjust the clay until the balloon inflates.Step 6
Hold the bottle and pull down on the knot in the balloon. Watch the balloon inside the bottle. What happens?
Step 7
Make a hiccup! Give the knot in the balloon a few quick tugs. Do you see the balloon in the bottle jump? That's what happens when you get the hiccups. When you hiccup, your diaphragm moves down quickly, which sucks air into your lungs – HIC!
You've made a model lung with balloons!
Learn more
What's going on?
Under your lungs, a big muscle called the diaphragm is working hard to help you breathe! When you breathe in, your diaphragm moves down. This creates more room in your chest, which lets your lungs fill with air.
Your model lung works the same way. When you pull the balloon knot down, that creates more room in the bottle. This lets the balloon inside the bottle fill with air, just like your lungs do!