The first thing you need to do is boil your water. We used about two cups of water per pint jar. While the water is boiling, you can make a shape out of your pipe cleaner. It needs to be able to fit in the jar without touching the sides or bottom.
Tie the string to the pipe cleaner, and tie the other end of the string to the pencil. The pencil sits on top of the jar and holds the pipe cleaner suspended above the bottom of the jar. Once you have your pipe cleaner shapes the correct size/length, set them aside.
*taken from http://britton.disted.camosun.bc.ca/snow/boraxsnowflake.html
The Science Behind the FunBorax is an example of crystal - "a solid with flat sides and a symmetrical shape because its molecules are arranged in a unique, repeating pattern."
Every crystal has a repeating pattern based on it's unique shape. They may be big or little, but they all have the same "shape". Salt, sugar, and Epsom salts are all examples of crystals. Salt crystals are always cube-shaped while snow crystals form a six-sided structure.
How do the Borax crystals grow?
Hot water holds more borax crystals than cold water. That's because heated water molecules move farther apart, making room for more of the borax crystals to dissolve. When no more of the solution can be dissolved, you have reached saturation. As this solution cools, the water molecules move closer together again. Now there's less room for the solution to hold onto as much of the dissolved borax. Crystals begin to form and build on one another as the water lets go of the excess and evaporates.
This also applies to snowflakes - As water cools the molecules move closer together. Since all water molecules are shaped the same (H2O) they align in a six sided crystal.