Science: States of Matter

Solids
The wood block is solid. A solid has a certain size and shape. The wood block does not change size or shape. Other examples of solids are the computer, the desk, and the floor.
You can change the shape of solids. You change the shape of sheets of lumber by sawing it in half or burning it.

Liquids
Milk is a liquid. Milk is liquid matter. It has a size or volume. Volume means it takes up space. But milk doesn't have a definite shape. It takes the shape of its container.
Liquids can flow, be poured, and spilled. Did you ever spill juice? Did you notice how the liquid goes everywhere and you have to hurry and wipe it up? The liquid is taking the shape of the floor and the floor is expansive limitless boundary (until it hits the wall). You can't spill a wooden block. You can drop it and it still has the same shape.
What about jello and peanut butter?
You can spread peanut butter on bread, but peanut butter does not flow. It is not a liquid at room temperature. You have to heat peanut butter up to make it a liquid. When you or your mom makes jello, it is first a liquid. You have to put it in the refrigerator so that it becomes a solid. These are yummy forms of matter with properties of a liquid and a solid.

Gases
Run in place very fast for a minute. Do you notice how hard you are breathing? What you are breathing is oxygen? You need oxygen to live. That's why you can only hold your breath for a certain amount of time.
You can't see oxygen. It's invisible. It is a gas. A gas is matter that has no shape or size of its own. Gases have no color.
Gases are all around you. You can feel gas when the wind blows. The wind is moving air. Air is many gases mixed together.