Childrens Science Experiments - Fake Lung Experiment

1. Use a clean and dry plastic bottle. Poke a hole down towards the bottom of the bottle so that you can cut around the base of the bottle.
2. Take one balloon and tie a knot at the open end then cut the end off the opposite end.
3. Carefully place this balloon around the end of the plastic bottle making sure that there are no gaps for air to get through.
4. Place the straw in the other balloon and wrap the rubber band around the neck to secure the balloon but make sure that it is not too tight (make sure that the straw is open for air to pass through) .
5. While holding the straw take the modelling clay, play dough or blue tack and form a closed lid around the opening. Again, make sure that the straw remains open and that no air can pass through the opening of the bottle.
6. Hold the bottle in one hand and gently pull the knot of the balloon with your other hand and watch as the balloon inside the bottle inflates.
7. More space is created inside the bottle when the knotted balloon is pulled and therefore air comes down the straw and fills the attached balloon with some air to fill that space. When you release the knotted balloon the balloon inside will deflate again.

This is a neat experiment to watch as the balloon lung expands when filled with air.

Our lungs work in a similar way: Air is taken in through our mouth and nose which is then passed through our windpipe and throat (like the straw takes in air when the balloon at the bottom of the plastic bottle is pulled), our lungs then fill with the air taken in (like the balloon inside the plastic bottle) and our diaphragm moves up and down increasing room in our chest (like the balloon at he bottom of the plastic bottle).

Kids Science Experiments - Fake Lung