The floating egg
You will need: One standard drinking glass, one raw egg, water and a few tablespoons of SALT. Fill the glass with as much water as you can, without overflowing it when you place the egg in the glass. The egg will sink to the bottom. Now carefully stir a couple of tablespoons of SALT into the water. The egg turns upwards and starts to "float"! If you add more SALT, the egg will slowly rise. You can make it sink again, by adding normal tap water. The explanation for this "sorcery" is simple: An egg is only a little heavier than the amount of water that it displaces. The dissolved SALT doesn't make the egg lighter, but it does render the water heavier. The more SALT you add, the lighter the egg becomes in relation to the water – until finally it floats.