This fun STEM activity will have kids erupting with excitement as they “hook” an ice cube into their string. This salt and ice fishing challenging project teaches kids some basic physics with salt and ice.
Supplies for Salt and Ice Fishing
- Cup of water (1 per participant)
- A few Ice Cubes for each person
- String
- Table salt
Activity Set up
Fill each cup about half full.
Pre-Activity Discussion
Ask kids if they know what happens when you put salt on ice. If you live in a cold climate, most kids will know that salt melts ice. Most kids, here in the Midwest, have heard an adult say “Wow, it’s icy, someone should put some salt down” or something along those lines. If you live in a warm climate, your kids may be new to this concept, but a little discussion will give them the basic knowledge to be successful in this activity.
Questions
- What temperature does water freeze?
- What temperature does ice begin to melt?
- Do you know what happens when you put ice in water?
- Explain that this is a trial-and-error activity and ask what is a trial-and-error activity?
How to go Salt and Ice Fishing
Give each kid a cup of water, a string and a bowl of ice. Explain to them that the are going ice fishing. No, not in the traditional sense, but that they will actually fish for ice.
Have them place a few ice cubes into the cup of water. Sprinkle some salt into the cup and place the string into the water. Then wait and see if they can catch an ice cube.
As they experiment with the activity. Direct their experience with critical thinking discussions. Some questions you can ask to drive them towards success:
- What would happen if you added more ice?
- How much salt have you added? Could you try to add more or less?
- How long did you leave the string in the water?
- What if you put the string directly on the ice cube?
Eventually a few kids will get an ice cube stuck on their string and erupt with excitement. Then a few more, and by the end everyone will have “caught” an ice cube. The trick is to use a lot of ice, a lot of salt and let the string sit on the ice cube.
What is happening?
The when you put the salt on the ice cube, the ice cube begins to melt. Then shortly after the ice cube refreezes. When you put the string on the ice cube while the ice melts and before it refreezes, the ice freezes around the string making it possible to pick up the ice with the string.
