## State of Matter

### Definition :

Matter is something that has mass and volume (takes up space). Matter can be found in several phases or states. The three most common phases of matter on Earth are solids, liquids and gases. Less commonly, we can also find matter as a plasma or Bose-Einstein (BE) condensate.

Solids have a fixed shape and volume. A solid's particles are packed closely together. There is not much space between the particles and there is little particle movement. A solid is not easily compressed.

Liquids have a fixed volume, but take the shape of the container in which they sit. There is not much space between the particles, but they can slide past each other and flow easily. A liquid is not easily compressed.

Gas fills the shape and volume of the container in which it sits. There is a lot of free space between its particles and they flow easily past each other. Gas can be compressed.

Plasma States of Matter

Plasma is one of four fundamental states of matter that contains a significant portion of charged particles in any combination of ions or electrons. Like gases, the plasma state has no fixed shape and volume and is less dense than the liquid or solid state. In modern science or technology, the plasma state of matter can be used for making television or many electronic devices.

Physical states

Molecules can shift from one physical state to another without changing their molecular structure (or chemical state). Water is still H20 when it is ice, steam or a liquid, even though its physical state has changed. Physical states can be changed by adding energy (i.e. increasing temperature or pressure) or releasing energy (i.e. cooling or lowering pressure). This does not change the matter's molecular structure. It is still the same matter or substance. When you heat a substance, you are adding energy to it. The movement of its molecules will increase until its physical state changes. The six ways to change the phase (state) of matter:

1. Melting changes a solid to a liquid. (i.e. dripping icicles)

2. Freezing changes a liquid to a solid. (i.e. lake freezing over)

3. Evaporation changes a liquid to a gas. (i.e. clothes drying on a clothesline)

4. Condensation changes a gas to liquid. (i.e. water forming on the outside of a cold glass)

5. Sublimation changes a solid to a gas. (i.e. ice cubes shrinking in the freezer)

6. Deposition changes a gas to a solid. (i.e. frost forming on the windows) These changes happen at precise temperatures for different substances. Scientists refer to these as melting point, freezing point, condensing point and boiling point. Water's melting point is 0°C, while its boiling point is 100°C.

Changes in state of matter