So, this is an experiment you can do at home with your kids (or without if you really want to). You get a glass and pop an egg into it. The you get some white distilled vinegar (you can use the rest of the vinegar to clean your washing machine, as in a previous post) Wait for 2 days and see what happens to the egg. Shine a torch through it. Very gently bounce it on the worktop. If you have had enough of the egg then just stick a knife in it and it will pop. Have fun.
WARNING THIS CAN BE A BIT PONGY OF VINEGAR!!