How many times have you been stuck inside with the kids on a cold winter’s day?

Take advantage of those days to do some awesome snow science while staying cozy inside! In this post you will discover how to make a snowman that magically gets bigger and bigger.

While you wait for your winter science experiment to be complete you can make some snow paint, make some Santa Claus exploding baggies, eat a snow cone (directions below), and discover 16 more snowman activities at the end of this post to keep the kids learning and engaged even during the coldest and longest days of winter.

If you enjoy this snow science experiment, you will love my new ebook, 5 SUPER COOL WINTER SCIENCE EXPERIMENTS FOR KIDS. It includes instructions for how to grow a snowy salt crystal house, how to make an indoor snowstorm, how to blast snowmen several feet into the air, and more! Click on the picture below for more details.

Getting Started with Snow Science

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To make our snowman baggies we gathered a few common household supplies:

• Zipper storage bags
• Permanent markers
• Alka-Seltzer tablets
• Snow

If you live in a place that doesn’t regularly get snow, no worries!

We didn’t have snow the first time I tried this snow science experiment either. To make my own snow I filled my Ninja blender with ice cubes and ground them up for 30 seconds or so until they turned into a fine snow powder.

We made snow cones with the extra shaved ice 🙂

Use a permanent marker to draw a snowman face on a zipper storage bag.

Fill the bag up with snow to make your snowman baggie.

Place 2-3 Alka-Seltzer tablets in the snow-filled baggie. Zip it up tight and then wait to see what happens!

Over the next 30-60 minutes watch as the snowman baggie expands bigger and bigger!

You may want to even set it in a larger bowl in case the baggie pops or leaks.

Snow Science

We LOVE doing science experiments with Alka-Seltzer. We have made film canister rockets, a lava lamp, and a glow-in-the-dark lava lamp using these fun little tablets.

So why does the snowman baggie expand?

Alka-Seltzer is made of citric acid and sodium bicarbonate (baking soda), which is a base. When the tablets are dry, the acid and base powders don’t mix, but as soon as they are immersed in water they mix and react to form carbon dioxide gas.

It is actually the same chemical reaction that happens when you mix baking soda and vinegar together. An acid plus a base mix to form carbon dioxide gas, which are the bubbles you see.

That carbon dioxide gas fills up the sealed baggie and may even make it pop open as the pressure increases!

You’ll notice that it takes a long time for the snowman baggies to inflate. Why do you think this is? What do you think would happen if you filled the baggies with hot water instead of snow?

Try it!

Let the kids experiment with snow science by varying the temperature of the water and adding more or less Alka-Seltzer. If you are feeling especially adventurous you could even use baking soda and vinegar to make the baggie explode!

More Winter Fun for Kids –>