LittleMan recently had a snow themed week in homeschool and I thought it would be fun to do the classic “Evolution of a Snowman” experiment where we show how a snowman changes from a solid to a liquid. Since LittleMan had not yet done an in depth study of the states of matter, we took some time to focus on that before doing the experiment.
It was a simple enough lesson. We picked up a library book on the subject, dug a half dozen balloons and some felt scraps out of our craft supplies, grabbed a few containers from the kitchen, and we set to work.
First we filled one balloon with air, the other two with water. One of the water balloons was made the day before and put into the freezer to freeze into a solid overnight while the other balloon was left unfrozen to represent a liquid. LittleMan explored these three balloons while I read the book aloud to him.
When the book mentioned that gases and liquids take the shape of the container they are in, but solids hold their own shape, I instructed LittleMan to squeeze all of the balloons to see which ones he could change the shape of. He struggled to try and make the ice change shape and was intrigued when he realized that he couldn’t.
I set out some different shaped silicone cupcake liners (circle, square, semi-circle, triangle) and measuring cup of water for LittleMan to further experiment and observe how liquids can change shape. He was surprised when I encouraged him to spill one of the cup cake liners onto the tray and watch how it didn’t take a shape but merely puddled up along the edge. Once he got over the shock of me encouraging him to spill, the concept really seemed to click with him.
Finally it was time to experiment with changing between states of matter.
We boiled a small pot of water with spices to observe how liquid becomes a gas, and how far that gas can travel in the “container” of our home.
At one point the conversation did take a little detour and I ended up drawing a diagram to explain the cycle of trees taking our carbon dioxide and releasing oxygen, us taking the oxygen and releasing carbon dioxide. There was also some discussion about why some balloons float (when filled with helium) and other balloons do not (when filled with carbon dioxide). That is the fun thing about homeschooling, because almost everything I do is meant to be a conversation starter with LittleMan, not a lecture, he frequently has questions and observation that lead to learning things not on the lesson plan.
Then we made our snowman. Now, since we don’t currently have any snow outside, I prepped the day before by putting 3 extra balloons of water, varying sizes, into the freezer. I placed heavy flat objects on top of each balloon to make a flat surface for later stacking. Once the water inside was frozen, I cut the rubber of the balloons off and stacked them onto a towel. Then I cut some snowman features from felt: a scarf, eyes, nose, buttons. LittleMan and I discussed how the snowman was a solid but how when solids get hot enough, they can become a liquid. We talked about how some solids (like metal) need much higher temperatures to melt, whereas ice only needs to get slightly above freezing to melt.
Vocabulary we learned throughout the lesson:
solid- state of matter that has its own shape
liquid- state of matter that can be poured
gas- state of matter that does not have its own shape and is often invisible
oxygen- gas we breathe in
carbon dioxide- gas we breathe out
helium- gas we put in balloons to make them float
steam- vapor or gas released when we boil water