States of Matter

General Chemistry Index

Where are we going with this? The point of this deck is to provide concepts,background information and examples related to the kinetic theory of matter. Using this model will help predict behaviors of substances within a variety of environments. 

States (Phases) of Matter

Why does it have two names?

There are five phases of matter.

Matter can be observed in different forms which change as the temperature changes. Most people are very familiar with three of the phases. The other two are a little less commonly recognized.

The differences in the phases (states) can be determined based on how a couple of physical characteristics are observed. Also, for the two less common, the state is determined based on (to keep it conversations) how the parts of the atom are arranged.

Before we define and look at characteristics of the different phases, a quick note. Matter will exist in different states depending on the temperature. As temperature changes, matter will undergo phase changes (state changes).

Let's start with the three common ones: solids, liquids, and gasses

The physical characteristics that determine the difference between solids, liquids, and gases deal with shape and volume.

Regarding shape, the question that separates solids, liquids and gasses is whether or not the shape is fixed and definite or not. Without banging on it, will the shape change to fit the shape of its container? If you place it on the desk, will the shape stay the same?

 

If you put a cube of metal, a glass beaker, or even a grain of sand on the desk, it will retain its shape. If you have a square jug of water, and pour the contents (the water) on the desk, the water will not remain a square. 

But ice would.

 

Regarding volume, the question that separates solids, liquids, and gasses is whether or not the volume can be changed as the volume of the container changes. If you have water in a glass and pour it into a bowl, the amount of the water stays the same. If you have 4 yards of gravel in a truck, then you spread all that out to make a driveway, the volume is still 4 yards of gravel. The shape changed (from the shape of the truck to the shape of the driveway). 

How the above two questions are answered determines if something is a solid, liquid or gas.

Solids

Matter in the solid state has BOTH a definite volume AND a definite, fixed shape.

Liquids

Matter in the liquid state has a definite volume BUT NOT a definite, fixed shape.

 

Liquids will keep the same volume as you pour from container to container, but they will take the shape of whatever container they are in.

Gasses

Matter in the gas state has NEITHER a definite volume NOR a definite, fixed shape.

 

Gases will expand or contract to fill the space available.

 

Two more phases of matter:

Plasma

Matter in the gas plasma has NEITHER a definite volume NOR a definite, fixed shape AND…

 

Plasmas are super high energy. So much so that the electrons have separated from the nuclei. This will be discussed more within the scope of kinetic theory.

 

Condensate / Bose-Einstein Condensate / BEC

Matter in this phase (state) is really more of a concept related to kinetic energy and motion of particles. Understanding it is better achieved within the context of kinetic theory. For purposes of this point of view, you can think of it this way.

 

Matter in this phase has collapsed into a big clump of electrons, protons, and neutrons, and has different properties as a result.

________

Who doesn't like a chart?

State	Shape	Volume	Other	Temperature
Bose-Einstein Condensate	N/A	N/A	Clump of sub-atomic particles	EXTREMELY Low
Solid	Definite	Definite		Lower
Liquid	Indefinite	Definite		Low
Gas	Indefinite	Indefinite		High
Plasma	Indefinite	Indefinite	Electrons “shaken off”	Higher