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The states of matter

Remember, matter is anything that has mass and takes up space. All matter is made up of moving particles. They don't stay still, they move about. All the material on earth is in three states - solid, liquid, or gas. The particles in a solid only move a little. They move more in a liquid, and they move around a lot in a gas. When you heat the particles up, they move around more. If you cool them down, they move less. That is why when you heat up a solid, it will turn into a liquid (like ice turning into water). And it is why water turns into ice when you take heat away by cooling it down.

Solids  The wood block is solid matter. A solid has a certain size and shape. The wood block does not change size or shape. Other examples of solids are the computer, the desk, and the floor. The particles in a solid are fairly squished together, and they don't move around very much. They just jiggle around in one place because they are pushed together as close as they can. They are a bit like bricks in a wall.

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Liquids Milk is a liquid. Milk is liquid matter. It has a size or volume. Volume means it takes up space. But milk doesn't have a definite shape. It fills the shape of its container. Liquids can flow, be poured, and spilled. Did you ever spill juice? Did you notice how the liquid goes everywhere and you have to hurry and wipe it up? The liquid is taking the shape of the floor and the floor goes on and on (until it hits the wall). You can't spill a wooden block. You can drop it and it still has the same shape. Liquid particles are still quite close together, but they move around more than solid particles. They move quite slowly (like a can full of caterpillars).

Gases Run in place very fast for a minute. Do you notice how hard you are breathing? What you are breathing is oxygen? You need oxygen to live. That's why you can only hold your breath for a certain amount of time. You can't see oxygen. It's invisible. It is a gas. A gas is matter that has no shape or size of its own. Gases have no colour. Gases are all around you. You can feel gas when the wind blows. The wind is moving air. Air is many gases mixed together.

The particles in a gas are much further apart, and they are moving around quite fast. They move fast in all directions, and they bounce off each other, and anything else they bump into. Think of them like a swarm of bees! The particles in a gas try to fill up whatever space is available. That's why a balloon is full, with equal pressure at all locations. By the way, wouldn't balloons be weird if all the gas was at the bottom?

Actually there are really four states of matter - solid, liquid, gas and plasma. Plasma is a kind of super-heated gas. We won't worry too much about that - we'll just stick to talking about the first three that you see in everyday life.