1. Matter
Chapter 9.2 and 18

2. What do all of these items have in common?

3. Matter
Anything that takes up space
Can be a solid, liquid or gas

4. What is dry ice?
CO2 that is below -78○C ( ○F) that has formed a solid

5. Where do we find CO2? Soda Carbon cycle 0.038% of air we breathe
Paint ball guns
Fire extinguishers

6. Why is it dangerous to touch dry ice with bare hands?
Frostbite or Tissue damage

7. Observe the dry ice in the front of the room.
Write down your observations…

8. Three states of matter
Solid
Liquid
Gas

9. Three States of Matter Solid State 9.2
Particles of a solid are packed closely together and are constantly vibrating in place
Attractions between particles are strong
Solids have a fixed volume and shape

10. States of Matter
9.2
Liquid State
Attractive forces are strong enough to cause particles to cling together
Liquids have a definite volume, but not a definite shape.

11. States of Matter
9.2
Gas State
In a gas the forces between particles are so weak that the particles no longer cling together.
Gases do not have a definite shape or volume.

12. What is the difference between a liquid and a gas?
You can see a liquid but you cannot see a gas.

13. If you cannot see a gas, what is the fog coming off the dry ice?
What appears to be fog or clouds, you are seeing little liquid water droplets. They float like a gas and don’t feel like a liquid because they are 1/1000 the size of raindrops.

14. 9.2
Changing States
Adding or removing energy can cause matter to change states
Melting – solid to liquid
Freezing – liquid to solid
Vaporization
Evaporation – liquid to gas at surface
Boiling – liquid to gas throughout
Condensation – gas to liquid
Sublimation – solid to gas