Fold the coffee filter in half so that it resembles a taco shell. Fold the half into wedge-shaped thirds and then fold it in half again. Cut across the pointed tip and cut a large triangle out of the open corner. Cut notches anywhere in the sides of the remaining piece. Unfold the coffee filter to reveal your model snowflake.
Snow is composed of small crystals of frozen water called snow crystals .
Air currents within the cloud lift the drop to high altitudes, where the temperature is below freezing, and the drop freezes into a tiny ice crystal. The process by which a vapor changes directly to a solid without becoming a liquid is called sublimation . Some snow crystals have long needles and the familiar flat shape with 6 extended arms. As snow crystals fall through the clouds, they collide with other snow crystals to form snowflakes . The size of a snowflake depends on the number of crystals in it.