1. Phases of Matter Solids
Now that you know all matter is made of atoms and molecules, let’s talk about the different types of matter that exist. Matter can exist as a solid, liquid, or gas. Let’s go over the characteristics of each of these phases of matter.

2. Phases of Matter Solids
What do you think of when you hear the word solid? Something strong and hard like a rock? That can definitely be true, and a rock is certainly a solid, but some solids can also be soft like a pillow. A solid is any type of matter that has a definite volume* and a definite shape.
*Volume is the amount of space something takes up. So matter that is a solid takes up a certain amount of space that doesn’t change.
Photo by Siim Sepp. Retrieved from Wikimedia Commons 6/15/09

3. Phases of Matter Solids
Characteristics of Solids
Solids have a definite volume (size).
Solids have a definite shape.
The atoms and molecules in solids are packed closely together.
The atoms and molecules in solids have very low energy.
More information about solids:
Chem 4 Kids - Solids
Solid particles stacked closely together.

4. Phases of Matter Liquids
Liquids are the next state of matter. Liquids, like solid have a definite volume (take up a specific amount of space) but liquids do not have a definite shape. Liquids take the shape of whatever container they are in.

5. Phases of Matter Liquids
Characteristics of Liquids
Liquids have a definite volume (size).
Liquids do not have a definite shape.
The atoms and molecules in liquids are close together, but have plenty of room to slide around.
The atoms and molecules in liquids have medium energy.
More information about liquids:
Chem 4 Kids - Liquids
Liquid particles close together with room to move.

6. Phases of Matter Gases Gases
Gases are the last state of matter. Gases do not have a definite volume or a definite shape. Because the molecules of gases are so spread apart, they aren’t able to keep their shape. They take on the shape and size of whatever container they are in.
Examples of gases include air, steam, and helium.

7. Phases of Matter Gases Characteristics of Gases
Gases do not have a definite volume (size).
Gases do not have a definite shape.
The atoms and molecules in gases are very spread apart and moving very fast.
The atoms and molecules in gases have high energy.
More information about gases:
Chem 4 Kids - Gases
Gas particles spread out and moving fast.

8. Phases of Matter Energy and Phases
Energy causes matter to change phases. If you add energy to a solid, the particles will begin to move faster and spread further apart until the solid becomes a liquid. You can see that process in action by taking a piece of ice out of the freezer and placing it in a glass. If you wait long enough, the energy in the room will melt the solid ice into liquid water.

9. Phases of Matter Energy and Phases
If you keep adding energy to the ice, for example by placing it in a pan on the stove, the molecules will continue to move faster and spread even further apart until the ice is all liquid, then the liquid will boil and turn into a gas.

10. Phases of Matter Energy and Phases
Energy can work in the opposite direction with phases too. If you take away energy from a gas, the molecules can slow down and become a liquid. If you take away energy from a liquid, the molecules can slow down enough to become a solid.
Click on the link and see what happens when you add and take away energy from different phases of matter.
Harcourt School States of Matter
Bitesize Matter & Solids Activity
Ice Cube Tray by Dr. Haggis. Retrieved from
Wikimedia Commons 6/15/09

11. Phases of Matter Energy and Phases