What is the world made of

What is the world made of

Have you ever seen anyone walk through a wall? Did you ever drink a glass of blocks? Have you ever played with a lemonade doll, or put on milk for socks?

Walls and blocks, dolls and socks. Milk and lemonade. Rocks and trees. All of these things are made of matter. The air in the breeze that blows the leaves. Water flowing in the creek. Everything on earth is made of matter. Lucky for us, it's easy to tell that not all matter is alike.

Matter comes in three states. It can be solid, liquid, or gas. Walls and blocks and socks are SOLIDS. Milk and lemonade and water are LIQUIDS. The air you breathe is a GAS. Some solids are hard and some are soft. But all solids hold their shape unless you do something to change them. A wooden block is hard. You can push it and pull it and squeeze it-it will always stay squared. If your baby brother pounds it with his toy truck, it may chip or break. But then the broken pieces will hold their shapes.

Modeling clay is soft. You can roll it out flat, like a pancake, or squeeze it into a ball. You can cut it with a knife or scissors. But if you leave it alone, it will hold whatever shape it is in. It is a solid.

Liquids have no shape. You pour a glass of milk for your little sister, and the milk takes on the shape of the glass. If she knocks it over, the milk spreads out on the tabletop. It flows over the edge like a waterfall. It drips and spatters on the floor. Milk is not round or square-it has no shape at all. Liquids can be thick, like a milkshake, or thin, like water. They can feel slippery, like cooking oil, or sticky, like maple syrup. But all liquids can be poured. And all liquids take on the shape of whatever they are in.