Matter

Matter is what the whole universe is made up of. One can say that every physical state is made up of matter. Starting from this page, the air you breathe, the liquids that you drink, everything is made up of matter. There are basically three states of matter - solid, liquid and gas. The state of a matter is defined by the kind of bonding the molecules in it has. Most of the matter can exist in any state depending on the temperature.

Solid
In solids, the molecules are tightly bound with each other and cannot move easily at all. That is the reason a solid object does not change its shape so easily and has a definite physical appearance. An example of solid matter is diamond.

Liquid
Liquids do not have any fixed shape and often take the shape of the container they are in. This is because the molecules in the liquid are loosely held together. In a liquid, the molecules move around each other, hence enabling the matter to flow as in the case of water.

Gas
Unlike solids and liquids, in gases, molecules are not held together at all. This enables a gas to fill any container evenly. And if you open up the container, the moving molecules escape into the open area. Because of such free and loose molecules, it is difficult to even touch and feel a gaseous matter.

1. Diagram showing the molecules in a solid object. Here the molecules are held tightly with each other and have almost no scope to move around.

2. This diagram shows how the molecules of a liquid substance are placed around each other. Here molecules are loosely bound and move around each other much freely than in solid objects.

3. This diagram shows that molecules move around freely to the level that they can almost escape in the atmosphere or can simply fill up any enclosed volume.