If water freezes and crystallizes, why no two snow flakes are alike?

Question

If water freezes and crystallizes, why no two snow flakes are alike?

Answer 1

Water molecules are polar (having an uneven charge distribution due to orbiting electrons).  They look like Mickey Mouse hats!  When ice freezes the molecules link together in chains and crystals that use up space less efficiently than if the molecules packed like (un-polarized) ball bearings.

There are infinite ways to stack billions of 'Mickey Mouse' hats and no two snow flakes are identical (except by rare chance?).