The Shape of Snowflakes

The shape of snowflakes results from bonding (and intermolecular) forces. 

Note that the combination of the bent structure of individual water molecules and the linear or almost linear nature of hydrogen bonds, H X—H (where X = O in water), leads to an ice structure characterized by rather large hexagonaUy shaped holes. The shape of snowflakes, one example of which is shown in Figure 11.4, reflects this overall hexagonal symmetry on the molecular level. When ice melts, some of the water molecules break off from the ice structure and fill the hexagonal... 

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