We don’t mean ice fishing as in “carving a hole in the ice and trying to hook some fish” ice fishing, we mean fishing for the actual ice itself!
What you need:
- Ice cubes
- Bowl of cold water
- Table salt
What you do:
First, drop a few ice cubes into your bowl of cold water. Have the children attempt to fish the ice cubes out using just the string. See if they catch any cubes. (Disclaimer: they shouldn’t be able to, but if they do, they have a new talent!)
Now, here comes the fun part! Lay the string across an ice cube and sprinkle just a bit of salt on the ice cube. Wait a bit, then pull the string up. The ice cube should come with it! You’ve officially caught an ice cube!
Questions to consider:
- Could you catch any ice cubes at first?
- What do you think happened when you sprinkled the salt on the ice cube?
- Why did the ice cube stick to the string?
Why it works:
As you may know from sprinkling it on your driveway every winter, salt melts ice. Salt lowers the melting point of the ice, making it more difficult for it to refreeze when salt is applied in large quantities. In our ice fishing activity, however, using such a tiny amount of salt melts the ice cube, but the water freezes it again quickly. By laying the string directly in the spot that melted and then re-froze, the string was frozen onto the ice. This allowed you to catch the ice cube!