1. Soak three eggs in vinegar...You really only need two, but I did an extra, because I know my kid...He was gonna wanna squeeze and squish the 'goo' out of one of those poor eggs. You soak the eggs for 24 hours and the vinegar basically eats the shell off. The real scientific explanation to this the child received was about the chemical reaction occurring as the vinegar reacts with the shell causing it to dissolve and allow the formation of the air bubbles in the vinegar as the gas escapes from the shells, allowing them to thin and just the egg lining or egg membrane to remain.
The next step was to prick the water enlarged egg. It was supposed to spout the water out. Of course, my kid squeezed the egg once it started to spout and tried to make it spew...needless to say, the egg exploded...remember there was 3 day old, sitting out on my counter top and in vinegar) egg yolk still in that egg membrane.
Next, place the sugar solution, shrunken egg into the older water solution. We had to start over with a new cup of water, because the child had thrown out the older water. When you place the sugar water egg back into regular water, it will slightly return to a more normal size. It reabsorbs water into the egg membrane to equalize the gradients again. Yes, the child had to prick the sugar solution egg once it was norml size again. Yes, he thought it would be equally cool to squish it too!! Don't forget we had the extra vinegar egg in the fridge all this remaining time. He remembered the extra vinegar egg about 2 days after the experiment ended and promptly poked it with a stick pin to squish it as well.
While we were conducting the above, we also boiled another egg and then soaked it in vinegar to eat the shell off of it. The child washed the shell off of it and it was bouncy, from short heights only. Yes, it was eventually squished outside as well. Needless to say, the child enjoyed this eggsperiment.