The rubber egg is a physical example of a chemical reaction occurring, as the acidic vinegar reacts with the calcium carbonate in the egg shell to break it down. The Eggs properties illustrate some of the core functions of a cell. This is a great way to learn about living organisms and work towards the badge requirements of the Beaver Experiment Badge or the Cub Scientist Activity Badge.
All living things are made up of cells
Empty Jam Jars with lids, clear plastic beakers or food containers
Spirit vinegar or malt vinegar
A bottle of cola
1. Discuss cells how they work and why we have them.
2. Carefully place the eggs in the jars. Fill the jars with vinegar and put the lids on.
3. Little bubbles should start to form on the eggshells. This means that a chemical reaction has begun. Leave the eggs until your next meeting.
4. Check on your eggs. The eggshells will have completely dissolved, leaving behind squishy 'rubber eggs'
5. Remove the eggs and carefully rinse them in water. Compare their size to a normal egg - are they bigger? What do they look and feel like?
6. See how strong the membranes are by squeezing some of the eggs until they burst; do this over a bucket or plastic sheet. Careful, it'll be messy! remember to save some eggs for the next step
7. Put one of your eggs in a jar of water and another in a jar of cola. The egg in water will swell as it absorbs water through the membrane, while the egg in cola will shrivel as the water leaves the egg. If you put the wrinkly egg in a new jar of water, it will swell up again.