It takes a secret ingredient — and a little old-fashioned chemistry — to amaze your friends with this neat trick.
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. Count to 5.
Pick up the loose end of the string. The ice will lift right out of the glass!
How it works: The salt is the secret ingredient. It lowers the freezing temperature of water, so it easily melts ice. That's why people in cold climates spread it on the road after a snowfall — and why the ocean rarely freezes. When you sprinkle the salt on the ice, some of the ice melts back into water, which is absorbed by the string. Seconds later, the water in the string refreezes (the ice underneath the string never touches the salt, so it doesn't melt). The result? The string is frozen to the cube, allowing you to pick it up.