Make Your Own Snow

When we think of crystals we often think of beautiful snowflakes. In this activity we will learn what snow is made of and watch how we can make a form of snow. We will also discover how snow has different forms, known as polymorphs, just like chocolate.


Make Your Own Snow

Watch the Make your Own Snow video on the right. Subtitles are available by clicking on the icon.

Once you have watched the video, why not try the activity yourselves by downloading our recipe and instruction sheet?

Download the Instructions

The PDF below contains instructions including what is needed to complete the activity, step-by-step instructions, and a health and safety guide.

Download the Instructions

 


What are you seeing?

In this experiment we add water to sodium polyacrylate to make a substance that looks like snow. Sodium polyacrylate is a polymer that can absorb more than 100 times its mass in water and its ability to absorb water means you can find it in nappies as well as fake snow!

Sodium polyacrylate is made up of two parts, sodium and polyacrylate. Polyacrylate is a polymer and polymers are made from joining lots of smaller molecules together in a chain a bit like a smaller version of a chain of rubber bands that you might make a bracelet into. In this experiment our polymer chain is made up of a chemical called acrylic acid joined together in a chain. In the dry powder the positively charged sodium ions are tightly bound within these polyacrylate polymer chains. When water is added the polyacrylate chains prefer to bind with the hydrogen atoms in the water instead, allowing sodium to move around and the polymer chains can start to unravel. Usually at this point the mixture forms a gel and starts to suck up water which is why it can be found in nappies. However, in our fake snow we use a different form of sodium polyacrylate that has more links between the chains and this time as we add water the powder swells up still but instead of making a gel it forms tighter, dryer flakes that look more like snow.