By: Ann Shepherd

The Science of Snowflakes

The story of a snowflake begins with water vapor in the air.  Evaporation from oceans, lakes, and rivers and transpiration from plants puts water vapor into the air.  Every time you exhale, you put water vapor into the air!
When air cools down, the water vapor it holds begins to condense into water droplets. High in the clouds, water vapor condenses onto dust particles. The water is said to be supercooled, meaning that it is cooled below the freezing point.  When the temperature reaches -10 C (or -14 F) the droplets start to freeze. As a droplet freezes, it becomes a small particle of ice surrounded by the remaining liquid water droplets in the cloud.  The ice crystals grow as water vapor condenses onto the surface, forming a snowflake in the process.

Make a Snowflake

Find out how crystals are formed using borax and a few other household ingredients.

You will need: String, a wide-mouth jar, pipe cleaners, boiling water, borax, a pencil, and blue food coloring (optional).

1. Cut a pipe cleaner into three sections of the same size and twist the sections together in the center. Make sure the points of your shape are even by trimming them to the same length.
2. Attach a piece of string and tie the opposite end of the string to the pencil. You will use this to hang your completed snowflake.
3. Carefully fill the jar with boiling water. For each cup of water add three tablespoons of borax. Add one tablespoon at a time and stir until the mixture is dissolved. Don’t worry if some of the borax settles at the base of the jar.
4. Add food coloring if you’d like to give your snowflake a nice bluish tinge.
5. Put the pipe cleaner shape into the jar so that the pencil is resting on the edge of the jar and the pipe cleaner shape is sitting freely in the borax solution.

Leave the “snowflake” overnight and in the morning you will find the snowflake covered in crystals!