There are 4 forms of matter-- solid, liquid, gas and plasma.
Solid...
A solid has definite shape and volume. Its particles are packed very close together, so solids can't move, but they can vibrate. Solids are made up of crystal shapes, which is the regular repeating order of particles (except for amorphous solids).
Liquid...
Liquids have definite volume but not definite shape, since it takes the shape of its container. The particles that make up liquids are close together, but not packed. Liquids have the ability to flow. Viscosity is the resistance of a liquid to flow.
Gas...
Gases have neither a definite shape or volume. Their particles are spaced far apart and they are able to move freely.
Plasma...
The particles of plasma are very far apart. It also has very high energy, which makes it quite dangerous. Although it is rare on Earth, it is the most common phase in the universe. The sun and stars are made of plasma.
Phases of matter also change into different forms. A physical change is a change that changes the substances physical appearence but not its identity. A chemical change is a process by which a substance becomes a new and different substance.
Solid --> Liquid = Melting
Solid --> Gas = Sublimation
Liquid --> Solid = Freezing
Liquid --> Gas = Evaporation
Gas --> Solid = Deposition
Gas --> Liquid = Condensation
Interesting Facts-
* A new phase of matter was discovered in 1995 called the "Bose-Einstein condensate" by two scientists Satyendra Bose and Albert Einstein. I didn't know there were 5 phases of matter.
*Matter is also related to light and electromagnetic radiation. I never thought matter was connected with light or electromagnetic radiation.
SOURCES: http://www.astro.washington.edu/larson/Astro150b/images/phases_matter.gif (Image)
http://www.chem4kids.com/files/matter_intro.html (Interesting Facts)
