Topic: - on October 21, 2002 at 10:07:56 PM CEST
Why are snowflakes symmetrical?
How can ice crystallizing on one arm 'know' the shape of the other arms on the flake?
Snowflakes are symmetrical because they reflect the internal order of the water molecules as they arrange themselves in the solid state (the process of crystallization). Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) to one another. These ordered arrangements result in the basic symmetrical, hexagonal shape of the snowflake. In reality, there are many different types of snowflakes (as in the cliché that 'no two snowflakes are alike'); this differentiation occurs because each snowflake is a separate crystal that is subject to the specific atmospheric conditions, notably temperature and humidity, under which it is formed.
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