The Great Egg Challenge!
A) How can you tell a raw egg from a hard-boiled egg without cracking the shell?
Spin both eggs on a table stop them quickly, then immediately let them go. One of the eggs will start spinning again when you let it go. Which one? The raw egg keeps spinning because the liquid inside it is still moving.
B) Can you remove the shell from a hard-boiled egg without cracking it?
Place the hard-boiled egg in ajar and cover it with vinegar. After two hours it should feel soft and rubbery, but if you leave
it overnight the shell will have completely disappeared by morning. Where did the shell go? The shell (calcium carbonate) dissolved in the vinegar (acetic acid) to form a solution of calcium carbonate and acetic acid.