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The states or phases of matter are used to classify the kinds of matter that exist. Matter can exist in three states: Wyoming, Utah, and California... just kidding! :)

Really they are: , , and .

Matter is made up of particles. These particles have characteristics specific to each of the individual states of matter. We can see how the particles move, their proximity to each other, and the shapes they can take.
View the different states of matter through the "magic magnifying glass."

As the temperature of matter increases, particles move faster because they have more energy. Decreases in temperature cause the particles to move slower. These changes in energy cause the changes of states of matter.

In a solid, particles have less energy, are tightly packed together (more dense) and do not move very much. Solids have a definite shape and volume.

In a liquid, particles have more energy, are less tightly packed (less dense), and can move freely. Liquids have definite volume but no definite shape (instead, they take on the shape of the container).

The particles in a gas have the most energy and are free to move around and so spread out rapidly. Gases do not have a definite shape or volume and expand to fill the entire container. Thus, as the temperature of matter increases, its density decreases (particles get farther apart).


Look closely at the concept map below to see this relationship visually.


Figure this out!

The metal lid on your jar of jam won't open, your mother tells you to run hot water over the lid. Why?

A. Heat lowers the motion of particles which makes the lid contract and be easier to remove.
B. Heat increases the motion of particles in the lid causing it to expand and be easier to remove.
C. The heat will cause the glass to break so you will not have to worry about removing the lid.
D. Your mother is crazy.
  Highlight the box below to see the correct answer!


Test your knowledge: Look closely at each of the following photos and determine if they represent a solid, liquid, or gas. Select your answer from the drop down menu. When you finish, check your answer by highlighting the box below.

1. Clouds
2. Juice
3. Ice
1. gas 2. liquid 3. solid
Highlight the box at the right for the answer.

Check your knowledge. Drag and choose an answer from each list to complete the following chart. When you finish, drag your mouse over the link below to check your answers.

ice definite shape/volume
water no definite shape; definite volume
steam no definite shape or volume

Drag your mouse over the link to view the answer key!

Review science safety rules here.

Get the plug-ins: Get Adobe Acrobat Reader , and Get Quicktime Player. (The Quicktime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE 7th grade science core.

Updated October 24, 2008 by: Glen Westbroek

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