Salty Ice Experiment

Why doesn't the ocean freeze in winter? Discover how salt can affect the properties of water with this salty ice experiment.

What You'll Need:
  • Two plastic cups
  • Water
  • Salt

Step 1: Fill two cups halfway with water. Add some salt to one of the cups and stir it up.

Step 2: Place both cups in the freezer or outside if temperatures are below freezing.

Step 3: Observe the cups. Which one freezes first?

You'll find that the salt in the water makes it harder to freeze. Depending on the amount of salt in it, saltwater may need to be 25 degrees colder than fresh water to freeze!

This is one of the reasons why salt is used to melt ice on sidewalks and streets. It's also one of the reasons why the ocean doesn't completely freeze when the weather gets cold.

Keep reading to find out how to make a model of a crack in the crust of the earth.

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