Exploring ice is an activity that children find interesting all year round. I remember the thin sheets of ice that would form in winter at what was usually the surface of a puddle in the gravel driveway in my childhood. The ice would cover the top, but when we stepped on it, there was no water under it! Since there wasn’t any water left in the puddle, how did that sheet of ice form, suspended above the non-existent water? Old and young experience that sense of wonder while observing natural phenomena. Journey through Dartmoor in the United Kingdom with blogger and artist Em Parkinson who also marveled at ice formations in depressions in the peat, and along the river.
Young children experience that sense of wonder when handling a block of ice that has an object embedded in it. How did that object get into the ice? They may be very familiar with the frozen water as ice cubes, icy sidewalks or icicles, but don’t really know the conditions in which water freezes to ice. Experiences observing changes in water as the temperature changes build children’s understanding of the properties of water and the reversible changes of freezing and melting. The Next Generation Science Standards puts this understanding in the Grade 2 performance expectation, 2-PS1 Matter and Its Interactions.
In the April 2013 issue of Science and Children, I wrote about observing my own teaching while having children handle ice shapes with small objects frozen into them. The three and four-year-old children shared their ideas about how the objects got into the ice. The explanations were simple, “It fell in,” and, “First they put the ice in, then the object, then more ice!” Only one child confidently related how liquid water becomes solid into ice in a freezer. The children’s responses informed my teaching. We needed more experience with observing water, and ice, as they got warmer or colder, as their properties changed. Luckily we were doing this in January and February when below freezing outdoor temperatures provided a full immersion experience with cold! Indoors the children made their own ice shapes with an object inside by putting plastic buttons into a cup of water and freezing them. Unexpectedly, some plastic buttons floated and some sank in the water.
There are very practical reasons for understanding that water becomes ice when the temperature is cold enough. New drivers coming home at night after a freezing rain laid ice on the roads, bicyclists who deal with morning ice on otherwise perfect-cycling-weather days, and those of us who put beers in the freezer to speed up their chilling process, need to be aware of the phenomena. For children it is more about eating the delightfully cold popsicle now rather than later when it is a disappointing lukewarm sweet drink, or putting the ice cube tray back in the freezer after getting some for your drink.
Now that the weather is warmer, children are exploring water in its liquid form: “washing” a fence, spraying water on chalk drawings to mix the colors, emptying the rain gauge, and watering the garden. Indoors, bathtime is an excellent time to begin exploring science concepts with young children. Read Sarah Erdman’s post in the National Association for the Education of Young Children’s online For Families, in which she shows us how to appreciate the small moments and make the most of every possible time to investigate the properties of that lovely material, water.