Activity: Snowflakes

On SCOPE's Ski Science episode, you saw Talia make some different snowflakes. Here's how she did it. TRANSCRIPT OF CLIP..

What you need

• pipe cleaners
• a big jar
• string
• hot water
• a pencil
• food colouring
• borax (available from supermarkets)

What to do

1. Create a star shaped frame for the snowflake out of pipe cleaners, and make sure your model is able to fit inside the jar.
2. Tie string around the pipe cleaners to give it that snowflake look.
3. Use a little bit more string to hang it from a pencil so that the frame will dangle nicely in the jar
4. Pour the hot water carefully into the jar, then spoon in some borax. About 4 tablespoons for every cup of water.
5. Add some food colouring to pretty things up a little.
6. Hang your snowflake in the solution and leave it over night.

What's happening?

The snowflakes made in this experiment are of course not real frozen water snowflakes, but they have a lot in common scientifically speaking.

If you create a 6 pointed star shape out of your pipe cleaners then it will resemble a real snowflake. Snowflakes will mostly form 6 sided shapes due to the way the water molecules (that are banana shaped) join together when they crystallise (or turn to ice).

This borax snowflake is also formed by crystallisation, the process that occurs when real snowflakes form. However, instead of cooling the water until in begins to crystallise, we dissolve lots of Borax in hot water and then cool it slowly. As the water cools back to room temperature, the amount of borax that can remain dissolved in it decreases, so it crystallises out. Some will end up as crystals on the bottom of the jar, but much of it will end up covering the pipe cleaner structure.

This is because the small fibres on the string and pipe cleaner provide a place for crystals to nucleate, or start. This is just like the grains of dust or pollen that can nucleate real snow flakes.

And just like real snowflakes - no two crystal patterns will ever be the same.