Grow a Snowflake in a Jar

(Borax Crystal Snowflake)

   

You will need:
* wire cutter or old scissors
* needlenose pliers
* string
* wide mouth pint jar
* white pipe cleaners
* blue food coloring (optional)
* boiling water (with adult help)
* borax (available at grocery stores in the laundry soap section, as in 20 Mule Team Borax Laundry Booster - NOT Boraxo soap)
* pencil

Directions:

Cut a pipe cleaner into three equal sections.

Twist the sections together at their centers to form a six-sided snowflake shape. Don't worry if an end isn't even, just trim to get the desired shape. The snowflake should fit inside the jar.

Spread out each end.

Add embellishments if desired.

Tie the string to the end of one of the snowflake arms.

Tie the other end of the string to the pencil. You want the length to be such that the pencil hangs the snowflake into the jar.

Fill a widemouth jar with boiling water.

Mix borax into the water one tablespoon at a time. Use 3 tablespoons of borax per cup of water.

Stir until dissolved, (don't worry if there is powder settling on the bottom of the jar).

If you want you can add a little blue food coloring now to give the snowflake a bluish hue.

Insert your pipe cleaner snowflake into the jar so that the pencil is resting on the lip of the jar and the snowflake is freely suspended in the borax solution.

   

Wait overnight and by morning the snowflake will be covered with shiny crystals.

   

Hang in a window as a sun-catcher or use as a winter time decoration.

Interior-Star Variation

Cut three 6-inch pieces of pipe cleaner, then cut six 3-inch pieces. Twist 6-inch pieces together. Center one 3-inch piece at the midpoint of a spoke, and twist onto spoke. Tighten twist with needlenose pliers. Repeat on remaining 5 spokes. Twist the adjacent ends of 3-inch arms together, and tighten with pliers.

The Science Behind the Fun

Borax 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.

References:
http://chemistry.about.com/cs/howtos/ht/boraxsnowflake.htm
http://underthesun.wordpress.com/2007/11/28/borax-crystal-snowflakes/