We learned that chemistry is the study of matter. Scientists who work with chemistry are called chemists. Chemistry can be found in many different professions.
Some chemists use their knowledge of chemistry to create new kinds of matter. Such as wild almonds contain cyanide and are toxic to humans, so scientists recreated this imitation chemical to make almond extract. We also learned that some chemicals are best left as natural.
The particle theory of matter is an explanation of what matter is made up of and how it behaves. According to this theory, matter is made up of tiny invisible particles, and that these invisible particles have empty spaces in between them.
These particles are continually moving randomly all the time. When heat is added to these particles, the particles movement speeds up and the particles spread farther apart. Since particles are attracted to each other, they tend to stay together rather than fly apart.
There are three states of matter. Matter can be classified as either; solid, liquid, or gas.
A solid has a definite shape to it the shape does not change. The solid as has volume to it. Volume represents the space something occupies. Ex; a rock is a solid shape, which also has volume.
A liquid has a definite volume, but it doesn’t have a definite shape. A liquid takes the shape of the container it occupies.
A gas doesn’t have a definite shape or volume. Gas also takes the shape of the container that it occupies.
The particles of a solid always remain the same size, what changes is the distance between each particle when they are in different states. The particles in a solid are the same distance from one another, the particles in a liquid are moving around one another, but remain close to each other. The particles in a gas move quickly and in different directions.
Changes in the State of Matter:
Matter can change its state from one state to another. This occurs when the matter is either heated or cooled.

When ice is heated, the particles begin to move faster, and the water changes from a solid to a gas. The particles of the gas are moving quickly and are further apart from one another. When the gas cools, the attractive forces pull the particles closer together, and the gas turns back into a liquid. If you wanted to change the liquid to its solid form, you would place the liquid in the freezer. The cool temperature would make the particles slow down, and when this occurs the matter changes from a liquid to a gas.
When gases are electrically charged, this is called plasma. It is considered the fourth state of matter and is found mainly in stars and nebulas in outer space.
Absolute Zero: Experiments have shown that particles can be cooled to the point of almost stopping. This is called, Absolute Zero. Scientists believe that at the temperature of -273 degrees Celsius, those particles stop moving. Absolute zero is the coldest possible temperature that could exist.
In 1924, Albert Einstein hypothesized that if Absolute Zero could be achieved, then another state of matter would result. In 1995, two scientists conducted an experiment that almost achieved Absolute Zero. This new matter that the scientists created is called the Bose-Einstein condensate.

Use this template to illustrate the particles in their different states. Use the chart of page 15.
Particles in a Solid Particles in a Liquid Particles in a Gas