YOU WILL NEED
Egg in its shell (it can be boiled or raw)
Glass of water, almost full
Carefully put the egg into the almost-full glass of water. The egg will sink.
Pour in two heaping teaspoons of salt and stir it around the egg.
Keep stirring in salt, two teaspoons at a time, until the egg starts to rise.
Salt water is denser than fresh water. When water becomes salty enough, the egg weighs less than the water—so the egg floats to the top