We’ve been waiting for a snowy day around here, because snow always lends itself to exciting winter games and science experiments. With leftover Alka-Seltzer tablets on hand, I had plans for exactly how we could use the snow this time around.

First, I drew a snowman’s face for Travis on a plastic bag. Note to self: next time use a sharpie! We had some inky orange and black hands later on…

Next we needed to collect fresh-fallen snow into our bag. Make sure you fill your bag almost to capacity with snow, or this experiment won’t work. We learned by trial and error!

Now drop in two Alka-seltzer tablets and seal the bag. You may want to place it on a towel, just in case the bag bursts…

Over the course of about an hour, we checked on the bag. The tablets slowly release gas that will make your snowman puff up more and more and more.

Here’s Travis poking a bag filled mostly with gas and leftover slush by the end.

I think the process would be even better if I had left the bag outside, so the snow didn’t melt simultaneously as the gas expanded – whoops!

The whole thing takes a while, of course, because the tablets react very slowly with freezing cold water. Because he grew impatient as we waited, I filled a second bag with hot water from the tap and we dropped in a few Alka-Seltzer.

They immediately fizzed and the bag puffed up with gas, and we talked about why the reaction happened so much faster in the heat.

Can’t wait for the next snowfall and the chance for more snowy games! What do you do with your kiddos to take advantage of a snow day? Please share in the comments!