It takes a secret ingredient - and a little old-fashioned chemistry - to amaze your friends with this neat trick.
WHAT YOU'LL NEED
Ice cube
Glass of water
String
Salt
WHAT YOU DO
Submerge an ice cube in a glass of water for a second or two. Let it float to the top.
Place one end of a length of string on top of the ice cube and sprinkle a little salt over it (at the point where the string touches the cube). Wait for 1 minute.
Pick up the loose end of the string. The ice will lift right out of the glass!
WHAT HAPPENED?
Ice cubes in water are continuously shrinking and growing because their surfaces melt and then re-freeze. The salt is the secret ingredient. When you add salt to the ice cube, it keeps the water from re-freezing at the surface of the cube. It does this by getting in the way of the water molecules that are trying to re-form into ice. But since the cube is surrounded by water, the salt eventually gets carried away into the rest of the glass. Only now, the new ice freezes around the string and holds it in place so you can lift the cube.
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Simple Science
Ice Cube on a String
WHAT HAPPENED?