By Meredith Brustlin, CMNH Educator
- Bowl(s) or container(s) that are freezer safe
- Fun items/trinkets to freeze (small plastic toys, rocks, coins, etc)
- Food coloring (optional, if you want colorful ice)
- Spray bottle
- Collect small trinkets and items from around the house and place them in a bowl or container
- Fill the bowl or container with water
- Add food coloring, if desired
- Freeze at least overnight (depending on the size of your container)
- Fill a spray bottle with water & a few spoonfuls of salt, shake!
- Take the container out of the freezer and turn it upside down on a cookie sheet, tray, or large dish
- Once the ice has unstuck from the container, remove the container and invite your young scientists to play!
- Direct them to spray the ice with the spray bottle. You can also have some other salt available that they can use to help melt the ice.
- Try to free some of the trinkets!
- There are so many angles that you can take for discussing the science of this project.
- The water: it changes from a liquid to a solid when we put it in the freezer! While you melt the ice with the salt water, it changes back into a liquid again! That’s two states of matter, can it become a gas? (Yes! Water vapor!)
- The melting: Salt lowers the freezing point of water. Ice melts faster when salt is added as the salt lowers the freezing point of the ice, this is known as freezing point depression. The more salt you add the lower the freezing point. This is why we use salt on roads in the winter to help melt the ice and make them safe!
The following Wee Ones video is designed for preschoolers and is all about "Melting" and would make a good video to watch together while doing this experiment!