Chemistry for Kids: Learn About the Three States of Matter
Everything is made up of atoms. Scientists use the word matter to describe what makes up every object. There are three basic states of matter in science. They are solids, liquids, and gases. The speed and density of atoms determine the state of matter of an object.
Water is an easy to understand example of the three states. Water can be either a solid (ice), a liquid (water) or a gas (steam). Matter can change from one state to another. If water is frozen it changes from a liquid (water) into a solid (ice). When water is boiled, it changes from a liquid (water) into a gas (steam).
A solid has a particular size and shape. A coin, wooden block, a table and a loaf of bread are all solids. Their shape can only be changed by using force. For example, you can change the shape of a loaf of bread by cutting it with a knife.
The atoms in a solid are tightly packed together. They don’t move very much because there isn’t much free space between the atoms. There's little room for movement.
A liquid does not have a particular shape. It will take the shape of the container it's put into. Water, juice, soda and milk are all liquids. Pour water into a cup. You will see that it takes the shape of the cup. If you spill water, it will spread out over the floor.
The atoms in a liquid are not as close together as those in a solid. They can freely move around and past each other. But they don't move as much as the atoms in a gas.
The atoms in a gas move around freely. When you see steam coming out of a kettle, you are seeing a gas. It seems to disappear into the air. When water is heated up, the atoms start to move very quickly and they become separated from each other. They start to move about in all different directions.
On a windy day, you can easily feel gases moving all around you. Air is made up of a combination of gases.
Gas can also be stored in a container and it will take it's shape. Helium is a gas that can be put into a balloon. The helium will take the shape of the balloon.