“Well, hello there, my science friends! Today, we’re diving into something we’ve all seen in our everyday lives but might not stop to think about: the changing states of matter. I know, it sounds super science-y, but it’s actually pretty fascinating—and way more common than you might realize. Let’s break it down and keep it simple, fun, and relatable. You’re going to love this stuff!”
That’s how I think the lesson is going to go. I don’t know about you, but I find it a difficult lesson to teach. I’m excited about the topic (who wouldn’t be, dry ice anyone?), but the students don’t seem to have the same enthusiasm.
It’s one of those topics that student encounter from an early stage and grows in complexity and understanding as they dive further into their science studies.
Why is Teaching the Changing States of Matter Tricky?
The concept itself sounds simple: solids, liquids, and gases can change from one form to another based on temperature. However, the challenge is that students might not immediately make the connection between theory and what they see in their everyday lives. The changing states of matter involve ideas that are invisible to students: molecules moving faster or slower based on heat energy, evaporation they can’t always see, and sublimation, which most haven’t even encountered, let alone heard of.
So, how do we make this science topic engaging, accessible, and—dare I say it—fun? I’ve got a few tips to help you turn the changing states of matter into something students will not only understand but get excited about.
Start with the Familiar
One of the best ways to break down the concept of changing states of matter is to start with what students already know (we’re all about activating prior knowledge, right?). So, ask students about everyday examples—like ice melting, boiling water, or the condensation they see on cold soda cans. These are things they’ve already experienced, which will help them connect the dots when it comes to understanding how matter changes states.
When I was first teaching the changing states of matter, I used to start with just definitions. But it didn’t take long to realize that students struggled to hold onto these abstract ideas without real-life examples. Students became much more engaged when I started incorporating things like ice cubes melting during lunch or the steam on a fogged-up mirror. They saw these changes happening in real time, which made the concepts stick!
Keep It Hands-On and Visual
For many students, simply hearing about the changing states of matter isn’t enough. They need to see it and, if possible, do it themselves. That’s why hands-on experiments are absolutely key to teaching this topic effectively.
You can have students melt ice cubes in their hands to experience the transition from solid to liquid (and bring it a step further, why does your hand feel cold – heat always moves from hot to cold). Or even better, get a simple setup to boil water and let students observe the liquid turning into steam. Watching these transitions happen before their eyes gives students a concrete understanding of the changing states of matter. You can even make it more interactive by asking them to predict what will happen to the water, the ice, or the steam before starting the experiment.
A little tip from experience: when students can touch and interact with the lesson, the concept becomes so much easier to grasp. It’s one thing to read about molecules speeding up and breaking free to form a gas; it’s another thing entirely to watch the transformation happen in real life.
How about some of these ideas?
- Ice Cube Melting Race: Couldn’t be easier! Grab a few ice cubes and see who can melt theirs the fastest (which could transform into a competition about who has the warmest hands!). You can use different methods like holding it, blowing on it, or putting it in warm water. It’s a great way to show how heat affects the solid-to-liquid transition!
- Boil Some Water: Nothing fancy here—just boil water and watch it turn into steam. You can even hold a cold spoon over the steam to show how it turns back into liquid water (condensation).
- Play with Balloons: Inflate a balloon, put it in the freezer, and see what happens (get them to write their name on the balloon or draw a face!). As the air cools down, it contracts and makes the balloon smaller. Then, when you take it out and it warms up, the gas expands again. This is perfect as a home assignment. Get them to take a picture of the balloon at the start, after it’s come out of the freezer, and then again after it has warmed up. Does leaving it in the freezer for an hour have a different effect than leaving it in overnight?
The more hands-on, the better! And remember, enthusiasm is contagious. If you’re excited about something, the people you’re teaching will catch on and get excited too.
Tackle the Invisible Parts
One of the biggest hurdles in teaching the changing states of matter is that much of what happens is invisible. For example, students can see ice melt but can’t see the water molecules speeding up as heat is added. They see the steam from boiling water but don’t understand the molecular motion behind it.
To address this, visual aids can make a world of difference. Use diagrams, videos, and animations to show students what’s happening at a molecular level. Interactive notebooks are another great visual aid, and they have the added benefit of making them slow down enough to process the information. Seeing a representation of water molecules speeding up or slowing down as matter changes states can help make the invisible visible. You could also ask students to draw their own diagrams, making them actively think about the process and how matter transitions between solid, liquid, and gas (this is what I use in my INBs).
Keeping in Real
One of the joys of teaching science is showing students how what they’re learning applies to the world around them. The changing states of matter is an excellent topic for this because it’s literally everywhere. From the frost on the windows in winter to the puddles evaporating after a rainstorm, students can observe the changing states of matter at home, on the playground, and in the classroom.
Encourage them to keep an eye out for examples in their daily lives. Maybe they’ve noticed ice cream melting on a hot day, or their breath fogging up a window. These everyday experiences reinforce the lesson and make the changing states of matter feel relevant rather than something confined to a textbook.
Expect some of them to come up with the way-out examples (lava/rock etc).
Making Abstract Ideas Concrete
Finally, don’t be afraid to use metaphors and storytelling to help students grasp the more difficult parts of the changing states of matter. This was one of my go-to methods each year. I told them to imagine that they were locked together with rods of iron. Then the music started, and they started to jiggle and move faster. Some of the rods/bonds break, and they can move more “fluidly” (pun intended). Next, the music went into gym mode, and each student could move any way they wanted. The energy and enthusiasm were off the charts! And more importantly, they got it.