There are so many fun ways to sneak in kids’ science  – make a rainbow in a jar, turn a flower two different colors, whip up some pop rockets. This simple balloon science experiment is a quick prep way to help kids learn about air pressure.

It’s a little bit of science magic!  For more science fun, check out our 30 Science Experiments in our shop!

Balloon Science Experiment Prep

I grabbed a plastic bottle, a balloon, a hammer and a nail.  I placed the balloon in the bottle so that it covered the mouth like the photo above. See?! I told you it was quick prep.

Uh Oh! The Balloon Won’t Inflate

I handed my son the balloon in a bottle and asked if he could blow it up for me. C grabbed it and enthusiastically started blowing.

After a minute of huffing and puffing to no avail, he handed the bottle back to me. “I don’t think I can do it.”  The balloon science experiment wasn’t off to the best start, but there was a reason for that.

Kids Science Blow a Balloon in a Bottle

“It’s because there’s air already in the bottle,” I told him. “And air takes up space.  Right now, when you blow into the balloon, there’s no space for it to blow up because the bottle’s already filled with air.”

Poking a Hole in the Bottle

We filled the bottle with water, capped it,  and I grabbed the hammer and nail. “Let’s poke a hole in the bottle and see if that helps.” We poked a small hole into the bottle about an inch up from the bottom. {Filling the bottle with water makes it a bit easier to hammer the nail through.}   kids science Balloon in a Bottle I dumped out the water, put the balloon back in, handed the bottle back to C and said, “Try again.” kids science Balloon in a Bottle What a difference a little hole makes in this balloon science experiment!

I explained to C that by poking a hole into the bottom of the bottle, we created an exit for the air in the bottle to escape, leaving room for the air he was blowing in the balloon.

While he blew up the balloon, I had him hold his hand over the little hole. “Do you feel the air coming out?” I asked him.  He nodded. “That’s the air leaving the bottle because you’re pushing it out when you blow air in the balloon.”

Staying Magically Inflated

When he finished blowing up the balloon, I had him put his finger over the hole and then hold up the bottle.   “Cool!” he cried. “It stayed blown up!” Kids-Science-Blow-a-Balloon-in-a-Bottle1 “There’s no air pressure in the bottle to push the air in the balloon out so it stays inflated,” I told him.  “But if you take your finger off…”   C removed his finger and, sure enough, the balloon deflated.   “Do you think if you cover up the hole, you could blow the balloon up?” I asked.

C shook his head. “No, because it would be like there isn’t a hole.”

“Right, the air in the bottle wouldn’t have anywhere to go, so you wouldn’t be able to blow up the balloon.”   C blew up the balloon several more times and discovered that he could only blow the balloon up until it reached the little hole — once the balloon covered up the hole, he couldn’t blow it up anymore.  This balloon science experiment was making a little scientist out of him!

balloon5 I explained that it was the same concept — the balloon was covering the hole, so the air in the bottle couldn’t escape,.  Therefore, there was no more room for the balloon to expand.

This balloon in a bottle was a super easy but fascinating kids’ science activity! And C was excited to have a whole new way of blowing up balloons.

Find More Kids’ Science

Make magic balloons, see how to make rainbows dance, walk on eggs and levitate pipe cleaners.  Also, check out our 30 Science Experiments in our shop!

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  1. What a FUN and SIMPLE activity! Thanks for sharing. It is so nice to see some cool kids science stuff out there ( as well as all the arty crafty messy fun!). This one is going on my pinterest for later…

    1. Gotta’ love FUN and SIMPLE, right?! I’m excited that you’re a fan of the balloon in a bottle. Let me know how it goes.

  2. This is my first time visiting your lovely creation! I am so looking forward to sharing this with my son. You’ve done a fantastic job explaining the experiments so that they are age appropriate. Thanks a bunch!

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