Chapter 1: Atomic Theory

The website for the introduction to states of matter that is HIGHLY recommended is chem4kids. Just click on the link and tour around the section on matter and atoms as an introduction to the topic.

The Kinetic Molecular Theory (at least the parts you are required to be aware of):
1. All matter is made of tiny particles (atoms and sub-atomic particles).
2. There are empty spaces between the particles (in fact matter is almost all empty space!)
3. The particles are always moving. In solids they are tightly packed and "bound" together, so they can really only vibrate. In liquids the particles have more freedom to move and they can slide around. Finally, in gases they have lots of space and can move about freely within whatever contains them (from a balloon to the Universe.... or to quote Buzz Lightyear "to infinte and beyond")
4. The more energy particles have, the faster they move. We can add energy by heating and remove it by cooling.
The kinetic molecular theory is strong enough to explain many of the scientific observations of chemists over the past millenia. Should you go on in Chemistry or Science in general, you will learn that more detailed and modern theories have arisen to fill the "gaps" and mistakes in the original theories...
1. All matter is made of tiny particles (atoms and sub-atomic particles).
2. There are empty spaces between the particles (in fact matter is almost all empty space!)
3. The particles are always moving. In solids they are tightly packed and "bound" together, so they can really only vibrate. In liquids the particles have more freedom to move and they can slide around. Finally, in gases they have lots of space and can move about freely within whatever contains them (from a balloon to the Universe.... or to quote Buzz Lightyear "to infinte and beyond")
4. The more energy particles have, the faster they move. We can add energy by heating and remove it by cooling.
The kinetic molecular theory is strong enough to explain many of the scientific observations of chemists over the past millenia. Should you go on in Chemistry or Science in general, you will learn that more detailed and modern theories have arisen to fill the "gaps" and mistakes in the original theories...