9.21 Describe the structure of the common form of ice.
Ice is a crystalline form of water. At atmospheric pressure, ice crystallizes in the hexagonal form, but at low temperature, it condenses to cubic form. The density of ice is less than water; therefore it floats on the water surface. Ice has a highly ordered three-dimensional hydrogen-bonded structure. (shown above) Each Oxygen atom is surrounded by four H atom tetrahedrally.