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Stage 1. Gaseous water cools. As the T falls, the average E k decreases and the molecules are increasingly affected by intermolecular attractions.
Stage 2. Gaseous water condenses. The slowest molecules are near each other long enough for intermolecular attractions to form groups of molecules which aggregate into microdroplets and then liquid.
Stage 3. Liquid water cools. The temperature decreases as long as the sample remains liquid.
Stage 4. Liquid water freezes. At the freezing temperature, 0ƒC, the attractions overcome the motion of the molecules.
Stage 5. Solid water cools. Motion is restricted to jiggling at each lattice site; further cooling to ñ40ƒC merely reduces the speed of this jiggling.
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