Solids, Liquids and Gases

Everything around you is made of matter, and most matter comes in three states: solid, liquid, and gas. Ice, water, and steam are all the same stuff — just water in three different states! Matter is anything that takes up space and has mass.

In a solid, the particles are locked together in a fixed pattern and can only vibrate on the spot. That is why a solid keeps its own shape and does not flow. Think of a brick, a coin, or an ice cube — they stay put unless something forces them to change.

In a liquid, the particles are still close together but they can slide past one another. This is why a liquid flows and takes the shape of whatever container you pour it into, yet keeps the same volume. Water, juice and oil are all liquids.

In a gas, the particles have lots of energy and spread out to fill all the space available. That is why a gas has no fixed shape or volume — it expands to fill its whole container. The air around you is a mixture of gases, even though you cannot see it.