Simple Science Projects for Kids: Salt and Ice

Are you missing your science class? Was your science fair canceled? You may not have a lab, but there are plenty of science experiments you can do with stuff around your house. These activities only need four things: ice, salt, string and food coloring.

Amazingly Strong String

Fill a glass of water almost completely full, and put in an ice cube. Cut a piece of string about 12 inches long. Lay the string on top of the ice cube. Could you pick up the ice cube with the string? Definitely not!

Now take some salt and sprinkle it on top of the string and ice cube. Wait a few seconds, then try lifting the ice cube again. The cube should stick to the string, and you can lift it!

How did something as simple as salt make this happen? Think about what we use salt for in the winter: melting ice. This is because saltwater melts at a lower temperature than freshwater. When you put salt on the string and ice, it melted the ice a bit, making a tiny tunnel where the string sat. When the ice froze again, it froze around the string, making it stick to the ice cube.

This is pretty cool on its own, but to really be an experiment, we need to change something and see what happens. What could you try changing? You could change the temperature of the water, or add salt to it. You could sprinkle sugar or another ingredient on the ice cube instead. Try and see what happens!

Salt and Ice Painting

You can also add some art to your science with just water, salt and food coloring. Freeze a big bowl of water. Once it’s frozen, put the ice chunk on a surface that you can get messy. Put food coloring on the ice chunk. What happens?

Now sprinkle some salt on the ice chunk. If you listen closely, you can even hear crackling where the ice is melting. Now put food coloring on. What happens?

When you put food coloring on the ice without salt, it just rolled off the surface. But when you added salt to the ice, it melted little tunnels into the ice that the food coloring could flow into, making an awesome—but temporary—work of art.

Looking for More Ideas?

Every summer, our friends at the Museum of Science and Industry come up with science projects that are easy to do from home. Check out Brain Games to try one for yourself!