We're going to discuss how the movement, arrangement, and shaped of molecules change in different states of matter. Solid, Liquid, Gas.
The molecules of matter in a solid state are only able to move in a vibrating motion and are very tightly packed. Solid matter also has a definite shape.
Here is an example of the arragement of the molecules tightly packed, and you can see how they would not be able to do anything but vibrate. Ice cubes would be an example of matter in a solid state.
Liquid molecules are a little further apart than the molecules in a solid. The molecules have just enough room to slide past one another, and there shape is able to change.
Here is an example of the molecule arrangement of a liquid, you can see the small amount of space in between the molecules that allows them to slide past one another. A glass of water shows you how the shape of the liquid is able to change depending on what shape the container is.
The molecules in a gas state are much further apart than they are in a solid or liquid state. Have enough room to freely move and bounce off one another. There is not definite shape of a gas, unless it is contained in something.
Here is an example of the molecules being able to bounce off one another because of their far apart arrangement. The balloon is what the air is contained in however the air around it has no definite shape.