Hello everyone, and welcome back to Science at Masefield! I’m Sophie Bennett, and I’m joined by the ever-knowledgeable James Harrington. Today, we’re diving into the fascinating world of states of matter—so, James, are you ready to get a bit scientific?Absolutely, Sophie. I’ve got my science hat on. So, let’s start with the basics: matter, which is basically everything around us, can exist in three main states—solids, liquids, and gases. Classic examples are ice, water, and steam. I always think of a glass of water on a cold day—ice cubes floating in the liquid, and if you heat it up, you get steam rising off the top.That’s a great image. And what’s really interesting is that what makes something a solid, liquid, or gas comes down to how its particles are arranged and how they move. In a solid, the particles are packed tightly together and just sort of vibrate in place. That’s why solids keep their shape, like a block of chocolate or a wooden desk.Exactly. But in a liquid, those particles have a bit more energy, so they can move around each other. That’s why water can flow and take the shape of its container. And then, in a gas, the particles are really spread out and moving quickly in all directions. Think of steam from a kettle—it just fills up the space it’s in.And the magic happens when you change the temperature. If you heat a solid, like ice, the particles start moving faster and eventually break free from their fixed positions, turning into a liquid. And if you keep heating, it becomes a gas. It’s all about energy!Speaking of energy, I’ve got a memory from when I was a boy. I left a bar of chocolate on the windowsill on a sunny day—big mistake. Came back, and it was a puddle! That’s a perfect example of how heat can change a solid into a liquid. And if I’d left it even longer, maybe it would’ve started to evaporate, though I probably would’ve eaten it before then.I think we’ve all had a chocolate mishap at some point! But it’s such a good way to see how temperature changes the state of matter. And it’s not just chocolate—everything around us is made of particles, and how they’re arranged and how much they move decides whether something’s a solid, liquid, or gas.So, let’s talk about how matter actually changes from one state to another. There are some key processes here: melting, freezing, boiling, condensation, and even some fancy ones like sublimation and deposition. James, do you want to break those down?Sure. Melting is when a solid turns into a liquid—like our chocolate or ice cubes. Freezing is the opposite, when a liquid becomes a solid. Boiling is when a liquid turns into a gas, like water boiling into steam. Condensation is when a gas cools down and becomes a liquid again—think of water droplets on the outside of a cold glass.And then there’s sublimation, which is when a solid turns straight into a gas without becoming a liquid first. It’s not as common, but you see it with dry ice. Deposition is the reverse—gas straight to solid. It’s a bit less obvious in everyday life, but it does happen!What’s really important is that all these changes are about energy. When you heat something up, you’re giving its particles more energy, so they move faster and can break away from each other. Cooling takes energy away, so the particles slow down and come closer together. And that’s why different materials have different melting and boiling points. Chocolate melts at a much lower temperature than, say, iron.That reminds me of a classroom experiment I did with my students. We sprinkled salt on ice cubes, and the ice started melting even though the room wasn’t that warm. The salt actually lowers the freezing point of water, so the ice melts faster. The kids were so excited—some of them thought it was magic, and we had a big debate about how it worked. It’s a brilliant way to see how different materials and conditions can change how matter behaves.That’s a classic experiment. And it really shows how science is all around us, even in the kitchen or the playground. The key thing is, temperature changes the energy of particles, and that’s what drives all these state changes.Now, let’s take all of that and look at the water cycle, which is happening all around us, all the time. Water moves through different states—evaporation, condensation, precipitation, and collection. It’s a never-ending journey, really.So, when the sun heats up water in rivers, lakes, or even puddles, it evaporates and turns into water vapour—a gas. That vapour rises, cools down, and condenses into clouds. When the clouds get heavy enough, the water falls back to Earth as rain, snow, or hail—that’s precipitation. And then it collects in rivers and lakes, and the whole cycle starts again.And you can actually see this in action if you watch a puddle after it rains. On a hot day, the puddle disappears much faster because the higher temperature gives the water particles more energy to escape into the air. Surface area matters too—a shallow puddle will evaporate quicker than a deep one.It’s amazing how something as simple as a puddle can show us the science behind the water cycle. And it’s not just about puddles—think about the River Thames. The weather patterns, the temperature, even the wind, all affect how much water evaporates and how much comes back as rain. It’s all connected.Absolutely. The water cycle is a brilliant example of how matter changes state in the real world, and it’s happening right outside our windows. It’s a reminder that science isn’t just in textbooks—it’s in our daily lives.Well, that’s all we’ve got time for today. Thanks for joining us as we explored the states of matter and the journey of water on Earth. We hope you’ll look at the world a little differently next time you see a puddle or a cloud. James, always a pleasure chatting science with you.Likewise, Sophie. And thank you to everyone listening. We’ll be back soon with more science adventures. Until then, take care and keep wondering!Bye for now!

Episodes

Y4 - States of Matter