1. Matter

2. The Phases of Matter There are FOUR states of matter:
Solid – keeps its shape and volume
Liquid – doesn’t have a definite shape, keeps the same volume, and can flow
Gas – doesn’t have a definite shape or volume and can flow
Plasma – doesn’t have a definite shape or volume and only exists at high temperatures (stars, sun, etc…)

3. Matter and Particles
All matter is made up of tiny particles called atoms and molecules.
The state of a substance depends on how fast its particles move and how strong the attraction is.

4. Solid Particles
In a solid, the particles vibrate in place and the attraction between them is strong. This causes the particles to lock together.

5. Liquid Particles
In a liquid, the particles vibrate faster and the attraction isn’t as strong. This allows the particles to flow around and over each other. Remember the water particles sticking together on top of the penny in the “Drops on a Penny” lab?

6. Gas Particles
In a gas, the particles move fast and overcome the attraction between them and separate from each other entirely. That’s why a gas will spread out in all directions – filling up a balloon, a room, or the atmosphere.

7. Melting: From Solid to Liquid
Melting is the change from a solid state to a liquid state.
The temperature at which a solid melts is called its melting point. The melting point is different for different solids. For ice, it is 0oC or 32oF.

8. Melting and the Particles
As you heat a solid, the particles in that solid will begin to move faster. They are absorbing energy! Eventually the motion of the particles will become great enough to overcome the attraction that locks the particles together as a solid. When that happens, the solid becomes a liquid because the particles start to flow.

9. Freezing: From Liquid to Solid
Freezing is the change from a liquid state to a solid state.
The temperature at which a liquid freezes is called its freezing point. The freezing point for different solids is different. For water, it is 0oC or 32oF.

10. Freezing and the Particles
If you cool a liquid, the particles will begin to slow down. They are releasing/losing energy! Eventually the motion of the particles will slow to the point where they cannot overcome the attraction between them. When that happens, the particles will lock together and become a solid.

11. Vaporization: From Liquid to Gas
Vaporization is the change from a liquid state to a gaseous state.
The temperature at which water changes from a liquid state to a gaseous state is 100oC or 212oF. This is known as its boiling point.

12. Vaporization and the Particles
As a substance is heated, its particles begin to move faster and faster. They are absorbing energy! During vaporization, the fastest particles are able to overcome the attraction of the particles around them and break free completely. These escaped particles become a gas (ex: water vapor).

13. Vaporization vs. Evaporation
Vaporization refers to the phase transition where a substance changes from a liquid to a gas.
Evaporation is a specific type of vaporization which occurs at temperatures below the boiling point of a liquid.
So vaporization includes evaporation and boiling.

14. Vaporization vs. Evaporation
Evaporation occurs at the liquid’s surface, but vaporization could happen below the surface when a liquid is boiling.
Think about water evaporating from a puddle vs water boiling in a pot.

15. Vaporization: Solid to Gas
Sublimation is the change from a solid state to a gas state.
This is a result of vapor pressure and temperature relationships. (Examples include dry ice and freeze drying food.)

16. Condensation: From Gas to Liquid
Condensation is the change from a gaseous state to a liquid state.
The temperature at which a gas condenses is called its condensation point. For water vapor, it is 100oC or 212oF.

17. Condensation: From Gas to Liquid
If you cool a gas, the particles will begin to slow down. They are releasing/losing energy! Eventually the motion of the particles will slow to the point where they cannot overcome the attraction between them. When that happens, the particles will lock together and become a liquid.