What Are the States of Matter?

Koko

Owlo! Owlo! Something really strange happened at lunch today. I have to tell you about it.

Owlo

Come in, Koko. You look like you just discovered something big. What happened?

Koko

I had hot chocolate, and I left it on the table for a while. When I came back, there was this weird skin on top. What was that?

Owlo

Oh, that is a wonderful observation, Koko. What you saw is actually connected to something called states of matter.

Koko

States of matter? That sounds really serious. Like, is matter in trouble?

Owlo

Not at all. Matter just means everything around us that takes up space. Your cup, the chocolate, even the air you breathe.

Koko

Wait, so everything is matter? Even me?

Owlo

Yes, even you. And matter can exist in different forms, which we call states. There are three main ones.

Koko

Three? What are they called?

Owlo

They are called solid, liquid, and gas. Let me show you something. Come over to the science lab with me.

Owlo

Here we go. I have three things on this table. An ice cube, a glass of water, and this balloon filled with air.

Koko

Oh, I see them. The ice cube is hard, the water is wet and sloshy, and the balloon is all puffy.

Owlo

Exactly. The ice cube is a solid. Solids are firm and they keep their shape. You cannot squish them easily.

Koko

Like my wooden pencil case, or a rock, or a cookie.

Owlo

Perfect examples. Now, the water in the glass is a liquid. Liquids flow and take the shape of whatever container they are in.

Koko

Oh! So if I pour water into a bowl, it becomes bowl-shaped. And if I pour it into a bottle, it becomes bottle-shaped.

Owlo

That is exactly right. You are thinking like a scientist, Koko.

Koko

And the balloon is the gas one, right? Because air is inside it?

Owlo

Correct. Gas spreads out to fill whatever space it is in. You cannot see air, but it is definitely there.

Koko

So my hot chocolate was a liquid. But what made that weird skin on top?

Owlo

Great question. When hot liquid cools down, it can change its state. Part of the chocolate started becoming more solid near the surface.

Koko

So it was turning from a liquid into a solid? Right there in my cup?

Owlo

Exactly. Matter can change from one state to another when it heats up or cools down. Ice melts into water when it gets warm.

Koko

And water freezes back into ice when it gets cold. I have seen that in the freezer at home.

Owlo

And when water gets very, very hot, it turns into steam. Steam is water that has become a gas.

Koko

I have seen steam coming from soup. So the soup was turning into gas a little bit?

Owlo

A little bit, yes. The top layer of the liquid was escaping into the air as gas. We call that evaporation.

Koko

Evaporation. That is a cool word. So matter is always changing around us and we do not even notice.

Owlo

That is a beautiful way to put it. The world is full of matter changing states, every single day.

Koko

Okay, I feel like I need to think about this. Can I try to say it all back to you?

Owlo

Please do. I would love to hear it.

Koko

So, everything around us is made of matter. Matter comes in three states: solid, liquid, and gas. Solids keep their shape, like ice or a rock. Liquids flow and take the shape of their container, like water or hot chocolate. Gases spread out everywhere, like air in a balloon. And matter can change states when it gets hot or cold. That is why ice melts, water freezes, and soup makes steam. Oh, and next time I leave my hot chocolate, I will just say it is doing science.

Owlo

That was a perfect summary, Koko. I think next time we could explore what happens when gases cool down and become liquids again.

Koko

Wait, gases can turn back into liquids too? There is always more to learn with you, Owlo.