Welcome to Five Minute Science, where we offer up cool science experiments you and your kids can do together using everyday household items, in about five minutes!
This week you get to refreeze an ice cube and learn some science too, from the experts at Let's Talk Science.
To show how matter can change from a solid to a liquid and back to solid again.
Be sure to ask your child what he or she thinks might happen before you do the experiment -- what result is expected when a wire is pushed down on ice?
An ice cube
Two unsharpened or dull pencils
Approximately 30 cm of thin wire
Wrap each end of the wire tightly around each pencil to make handles.
With the ice cube on a dish, place the wire on the ice cube.
Using the handles apply pressure with the wire on the surface of the ice cube.
The wire will melt its way through the ice cube. This process can take several minutes.
When the wire is halfway through the ice cube, lift up the ice cube.
Explaining the Science:
Did you see the wire melt through the ice, and then the ice refreeze, trapping the wire inside? Why do you think this happened? The scientific explanation is that when you apply pressure (push) on the ice cube, its temperature increases. This causes the ice cube’s temperature to rise and the ice slowly melts. As the ice melts beneath the wire, the thin space above the wire is filled with the melted water. The air in the room (or the atmospheric pressure) presses down on the melted water, but the pressure is less than when you pushed down on the wire, and the temperature of the air around the ice cube is cooler, so the water refreezes. After several minutes, the wire will be frozen inside the ice cube. Cool!
While this experiment is simple and appropriate for any age, adults should supervise children – especially when handling pencils and wire. In the Ontario Science and Technology curriculum, Understanding the Properties and Changes of Matter is taught in grades 2 and 5.
What happens if you try this experiment in a warm room?