We found out that salt lowers the  freezing point of  water. The  salt makes the  ice melt a little bit. Then the thread sinks into the unfrozen ice (where the salt hits it) and then it traps the thread.

 

WHAT YOU NEED:

 

- 1 ice cube to do the experiment on

- 1 cup full of ice water, with ice cubes in it

- 1 6-inch piece of thread

- salt

- spoon