Solid, Liquid, or Gas? The Three States of Matter

Imagine you pour orange juice into a glass. The juice moves and fills the bottom of the glass. Now add some ice cubes. The ice keeps its shape — it doesn't pour! And all around you, invisible air fills the whole room. That's three different states of matter right there. Can you spot them? Think about what is different about the ice, the juice, and the air before you read on.

Everything around you is made of matter. Matter is anything that takes up space and has mass — in other words, has some weight to it. Scientists sort all matter into three main groups called states: solid, liquid, and gas. **Solids** keep their own shape. A rock, a wooden spoon, and your pencil are all solids. You cannot squash them into a different shape easily. The tiny particles inside a solid are packed tightly together and held firmly in place. **Liquids** flow and take the shape of whatever container they are poured into. Water in a bottle takes the shape of the bottle. Pour it into a bowl and it takes the shape of the bowl. The particles in a liquid are close together but can slide past each other, which is why liquids can flow. **Gases** spread out to fill every part of their container — or even a whole room. You usually cannot see gases. Air is a mixture of gases. The particles in a gas are spread far apart and move around very quickly. **Worked example — water in its three states:** Water is brilliant because we can see all three states in everyday life. Ice is solid water — it holds its block shape. Liquid water flows and fills your cup. Water vapour is a gas — it rises off a hot drink as steam. Same material, three different states! One key test: does it hold its own shape? A solid says yes. A liquid says no — it copies its container. A gas says no, and it also spreads out to fill all the available space.