2. Understanding Gases

3. §fill balloons §propel bullets §form the Earth’s atmosphere §are invisible §have the ability to expand and contract §are made of atoms or molecules

4. What Do Gases Look Like? If we could magnify gas atoms and molecules a hundred million times they would look something like the wildly flying Ping- Pong balls of state lottery games.

5. What happens when you heat gas molecules? Let’s try this experiment and find out.

6. What is inside of this bottle? PREDICT: What will happen to the balloon if the bottle is placed in hot water?

7. What do you see happening to the balloon? Click mouse to continue

8. What is making the balloon expand? What is happening to the molecules inside the bottle? Click mouse to continue

9. What would happen if the air inside the bottle was cooled? Let’s replace the hot water with ice and find out!

10. What is happening to the balloon now? Click mouse to continue

11. And now? Click mouse to continue

12. And now? Click mouse to continue

13. What is causing the balloon to collapse? What is happening to the molecules inside the bottle? Click mouse to continue

14. The Science Behind it All Heating gas causes molecules to Speed up They actually move so fast that they collide with each other with great force. This increases the pressure inside the bottle causing the balloon to expand in response to the increased pressure inside the bottle.

15. Cooling the gas inside the bottle causes the molecules to Slow down They move very slowly and contact each other with much less force. The molecule pack in closer together.