Next, we soaked the eggs in water and sugar solution respectively. She observed that the egg sunk in water but not in the sugar solution. That’s because sugar solution is denser. At first, our egg didn’t float in the sugar solution and I had to add more sugar.
After this, there was nothing else to do but to wait. She asked for another egg to design an experiment. Her instructions were to put an egg into the glass, pour baking soda, pour water and use a wooden chopstick to poke. I asked her 2 questions.
1) What will happen when water is added to baking soda?
2) What will happen when she poked the egg?
She gave me the classic ‘I don’t know’ answer. I assured her that it was ok not to have an answer. Experiment is all about finding answers. I loved it when she design her own experiment.
She soon found out that water did no react with baking soda and that the egg will break when poked.
The next day, we got 2 different coloured eggs.
I explained that the sugar solution had entered the egg. She was super happy.
We used a needle to poke and saw sugar water shot out.
She had fun squeezing out the egg yolk.
Busy Bee was patient throughout out experiment, joining in on my laps at times.
What she learnt:
1) Egg shell dissolves in vinegar.
2) Vinegar is an acid.
3) Egg shell is made of calcium carbonate which reacts with vinegar.
4) Sugar solution has a density that is higher than water. This is why the egg will float in sugar solution.
5) Egg has a semi permeable membrane and water can enter. This is why the egg in sugar solution turned brown.
There are lots of other science concepts that can be learnt through this experiment. I adapted the above for her age. Science Sparks listed the entire science concepts.