Thursday, June 26, 2014

Air Pressure: Exploring How Lungs Work

Lungs make a great demonstration of how air pressure is used in our body.   We love to explore anatomy and physiology and this experiment is a great way to introduce a basic concept.  

This activity also builds really nicely on the Water Bottle Fountain activity that we have previously posted.   

We started by discussing how we get air into our bodies.  We put our hands on our chests and felt it expand (or go out) as we breathed in and contract (or go in) as we breathed out.  We then spoke about how we use our lungs to get the air we need.

But how does it get into our lungs?  We spoke about how the air goes in through our nose, down our air passages and into our lungs.   Then we got ready to build our lungs.

We used a straw for the air passages and inserted it into a balloon (our lung).  We secured the balloon with a rubber band to the straw.

We then took a water bottle to represent the chest cavity. One important note: make sure your bottle is strong - we used a water bottle the first time but it was weak and deformed easily.  When we repeated the experiment we used a tonic water bottle, and it was much stronger.  We still had to reinforce the bottom with tape to help prevent it from deforming.   The great thing about the water bottle was that the ridges felt like our ribs, but it was difficult to do the experiment.

With both bottles, we cut off the bottom of the bottle leaving a large enough volume for the balloon to hang inside.  Then we threaded the straw through the mouth of the bottle with the lung inside and sealed the top using molding clay.

As you can see. little Bear lost interest for a while and engaged in a game of peek-a-boo with the neighbors' dog.  Bug stayed pretty focused.

To make our diaphragm at the bottom we used a second balloon.  We tied the balloon closed and cut off the top third of the balloon.  The open portion of the balloon went over the cut part of the bottle and was secured in place with tape.  So now we had our model of a lung - air passages into the lung which sits in the chest cavity and the diaphragm muscle below.

We pulled to test it out and pulled our airways right out of the chest - whoops!  So make sure you hold the chest when making it breathe.

After a quick fix we were working again.

Now to make our lungs work (we took additional pictures without the kids to make sure we can show you the movement of the lung - thanks hubby!):

Breathing in: when the diaphragm muscle contracts it pulls down - so we pulled down on our diaphragm by pulling the tied portion of the balloon down.  

This expansion increases the volume which decreases the air pressure compared to outside.  Air flows in through the air passages from high pressure (outside) to low pressure (inside the lungs) and inflates the lungs.  We saw our lung balloon get bigger!

Breathing out:  when the diaphragm muscle relaxes it goes up - so we released our balloon.   

This decreased the volume of the chest cavity which increased the pressure in the cavity and on the balloon.  The air flows out through the air passages from high pressure (inside the lungs) to low pressure (outside) and deflates the lungs.  We saw our lung balloon get smaller!  

We saw it get even smaller when we pushed up on our diaphragm!

You can repeat these steps to mimic how we breathe in cycles.


  • straw
  • tape
  • strong clear plastic bottle - tonic water bottle worked well
  • rubber band
  • clay/silly putty
  1. Insert a straw into the mouth of the balloon and secure with an elastic band.
  2. Cut off the bottom of a plastic bottle and wrap a few pieces of tape around the bottom of the bottle to reinforce it.
  3. Thread the straw through the mouth of the bottle so that the balloon is inside the bottle.  Seal the mouth of the bottle with clay and wrap in tape to make it extra secure.
  4. Tie a balloon closed and cut off the top 1/3.  Take the open part of the balloon and cover the open bottom of the bottle.  Secure the balloon to the bottle with tape.
  5. Suck most of the air out of the lung-balloon.
  6. Pull down on the knot in the balloon on the bottom of the chest and see what happens to the lung.
  7. Release and see how the lung changes.


Wednesday, June 18, 2014

Air Pressure Puffer Game

We have really been enjoying our air pressure activities over past few weeks.  I saw an air pressure game on Kids Activity Blog and thought Jelly Bean and Jumping Bean would love it, but we decided to add some math to our activity.

The puffer is a great way to demonstrate air pressure.  The sealed bag traps air inside it and when you press on it, air puffs out of the straw.  Today, we are going to test how far our puffer will move different objects and measure the distance each object will travel.

Jelly Bean and Jumping Bean predicted which object would move further using our puffer.  They then placed all the objects in order from predicted shortest distance to the longest distance.

Then the fun begins- slamming down on the baggie.  The girls loved hearing the puff of air shoot out of the straw.  

Jelly Bean and Jumping Bean helped each other measure the distance each object moved and recorded each one on a post-it note.

After all the objects were tested, the girls looked at the numbers on the sheets of paper and ordered them from smallest to largest.

And, the results!  The objects that moved the furthest were the light objects - some were even hollow.  We looked at the rubber ball and discussed that it is heavier than the others.  We also reviewed what we learned about density from our Float-Sink activities and determined the rubber ball did not move because it is was heavier due to its greater density.  The pony bead was more flat, and the air passed over it, therefore, it did not move.
  • plastic baggie
  • 2 sponges
  • straw
  • tape
  • objects to puff- we used a pony bead, plastic ball, rubber ball, Easter egg, and pompom
  • tape measure
  • paper
  • pencil
  1. Make the puffer by placing a straw between two sponges and putting them into a plastic baggie.
  2. Tape the baggie shut so it does not open during the activity.
  3. One at a time, place an object about one inch in front of the straw.
  4. Press down on the sponges in the baggie.
  5. Measure the distance the object travelled.
  6. Record the distance on a sheet of paper.
  7. Order the distances from smallest to largest.

Thursday, June 12, 2014

Egg in a Bottle

Want to do a magic trick?   Amaze your kids by getting an egg in a bottle without touching it - all while exploring the strength of air pressure.

This was a great experiment to show kids the strength of air pressure.   We had a few attempts to get this egg-septional experiment to work.

We set up the experiment and spoke about how we could get an egg into a bottle.  One suggestion was to break it up and put it in.  While that would work it would involve us touching the egg.

So then we took the egg off the top of the bottle, lit a strip of paper and dropped it into the plastic bottle.  Then, the egg was placed back on the top of the bottle.   The egg was rattling as the hot air escaped from the bottle.  Then, it got quiet, and we waited to see the egg go into the bottle.  Instead, out bottle collapsed in on itself.  Whoops.

The egg was stuck on the bottle pretty tightly - we could not pull it off until we carefully released the seal.

Well that was pretty cool and showed us how strong air is - it could crush a plastic bottle!  But our egg was still outside our bottle.  So after multiple attempts (involving almost setting off a fire alarm with all the smoke) we decided we had to use a stronger container - preferably a glass one.  So we scrounged around the kitchen and found a glass bottle that seemed around the correct size.

So we put a birthday candle in the glass bottle, lit the candle and placed the egg on top.

Our egg still did not go into the bottle.  It sealed on there pretty tightly though.   Again we carefully released the seal and thought about what we could do.   

So we decided to sing happy birthday to the egg.  We stuck the candle in the egg and lit it.  We all sang happy birthday while holding the candle under the glass jar.  

We held the egg at the bottom of the jar.   The candle continued to burn until it was out of oxygen, and then it started to slowly slip into the jar.   

 We were so excited!!   Our egg broke as it went into the jar, but it definitely slipped up into the jar.  

We had a lot of fun with the experiment - even though it took a few attempts.  But, that is how science works: try, try, try again until you figure it out.

So what happened here:
When you heat up the air inside the container it expands and comes out of the container creating a low pressure environment within the container.  The air outside the container is a higher pressure which then pushes the egg into the container (or pushes the plastic bottle in so that it collapses).  

  • boiled egg, peeled
  • glass container with a mouth narrower than the width of an egg
  • birthday candle
  • lighter

  1. Boil and peel an egg.
  2. Stick a birthday candle into the egg.
  3. Light the candle and hold it below the inverted jar and sing happy birthday.
  4. Gently hold the egg against the mouth of jar and wait.
  5. It will slowly be sucked up into the jar.

Thursday, June 5, 2014

Air Pressure: Making a Bottle Water Fountain

Jelly Bean and Jumping Bean have been rather fond of balloons lately, and what I mean about rather fond of, is obsessed.  And now that it is summer, they love playing with water outside.  So, when I saw this activity at Life with Moore Babies, we had to do it!  We are going to investigate air pressure using these favorite things (balloons and water).

We gathered up our supplies from around the house: empty water bottle, funnel, straw and balloons and with minimal preparation we began our investigation.

First, we talked about how air is all around us.  I asked Jelly Bean and Jumping Bean what is inside a balloon when I blow it up.  "AIR!"  they both yelled.  We discussed how even though it is invisible, or you can't see it, air is still there.  To demonstrate this concept, a blown up balloon was attached to the mouth of a plastic bottle.  The girls were amazed that the balloon did not deflate.  The air inside the "empty" bottle was applying pressure, or pushing against the air inside the balloon.  Therefore, the air inside the balloon did not come out making the balloon whiz all around.

To demonstrate the air pressure even further, Jelly Bean and Jumping Bean made a water fountain by exploring what happened when you applied air pressure to a bottle filled with water.

First, they poured water into a plastic bottle with food coloring for fun!  We used a funnel just to make it a little easier!  I had pre-cut the bottle with a small hole cut in the side and secured a straw through the hole with clay (to seal any leaks).  One note: make sure your straw is pointing up so that the water does not flow out.  Then, an inflated balloon was attached to the mouth of the bottle.

Once the balloon was released, the air pressure from the balloon caused the water to flow out of the attached straw.  That was a lot of fun to watch, and we did it over and over again!


  • plastic bottle
  • balloon
  • straw
  • water
  • funnel optional
  • clay


  1. Blow up a balloon, and ask what is inside. 
  2. Attach the balloon to the mouth of an empty plastic bottle.
  3. Discuss that the balloon remains inflated because there is air in both the balloon and the bottle.  There isn't any room for the air to go when the balloon is released so it stays inflated.
  4. Attach a straw to the plastic bottle by poking a hole in the bottle and sliding the straw inside.  Make sure the straw is pointing up.
  5. Press clay around the hole and straw to seal anywhere that may leak. (ours leaked so we added more clay)
  6. Pour water into the bottle.
  7. Place an inflated balloon over the mouth of the plastic bottle.
  8. Let go of the balloon.
  9. Watch the water flow out of the straw making a fountain.
  10. Repeat.