Solids, Liquids, and Gases
Everything around you is made of matter. Matter is anything that takes up space and has mass. It comes in three main forms: solid, liquid, and gas.
A solid keeps its own shape. A rock, a pencil, and an ice cube are solids. You can pick them up, and they do not change shape.
A liquid has no shape of its own. It takes the shape of whatever holds it. Water poured into a cup looks like the cup. Pour it into a bowl, and it looks like the bowl.
A gas has no shape either, and it spreads out to fill any space. The air in a balloon is a gas. It fills the whole balloon.
Water can be all three. When it gets cold enough, it freezes into ice, which is a solid. When it gets hot enough, it boils and turns into water vapor, which is a gas.