Ice Property #1: Ice is less dense than water.
Ice Property #2: Ice can preserve things.
We'll test both of these at the same time. First, take some fruit and separate it into two samples. Half of the fruit will be frozen and the other half will be left in the air. Which one do you think will stay more fresh?
Take half of the fruit and put it in a clear, plastic container. Add water to the container until all of the fruit is covered, but be sure that the container isn't full! The ice will need room to expand. Fill a tall water bottle about 2/3 full, then mark the water level on the side of the container with a marker or piece of tape. Predict where the water level will be after it has frozen to ice, then mark your prediction.
Put your fruit container and water bottle in the freezer (and let the other fruit sit out at room temperature) for about 24 hours. Then take your containers out of the freezer and mark the actual level of the ice in the water bottle. How close was your prediction? Leave the fruit container at room temperature and allow the ice to melt. (If you're anxious, you can further explore the properties of ice by chipping away at it or finding ways to melt it faster, such as a hair dryer. But be sure to wear safety glasses!)
Ice Property #3: The freezing point of water is 32 degrees Fahrenheit (or 0 degrees Celsius). When water reaches this temperature, the water molecules start to lock into place instead of moving around freely.
Ice Property #4: Adding salt lowers the freezing point of water. (So does adding sugar or almost anything else.)
For more kid-friendly information and ice experiments, visit here or here. For a fun video that explains why water expands when it freezes, click here. And for a gorgeous ice art project, visit here.