Place this bag in the other pocket. Then open the bags after one or two days to see what has happened. Let the children enjoy the sprouts that have grown in the moist towel. 30 minutes of activity. Full day to see the effects.
Water expands when it freezes.
Frozen, or solid, water can break bottles and pipes, and causes cracks in rock and sidewalks. But water as a solid weighs less than water as a liquid. For example, ice usually forms on top of a river. This then creates a blanket-effect below for the fish living in the river. If ice formed on the bottom of the river, some rivers would never melt in the spring.