ATMOSPHERE

3. This gas did not show up into our atmosphere until about 2 billion years ago.
5. The total energy of the particles that make up an object.
7. The ozone layer protects us from these rays.
8. The amount of this gas in the atmosphere depends on location and time of day.
10. The original atmosphere was stripped away by these.
11. These processes are responsible for the decrease in temperature with altitude.
13. This is a blanket of gas bound to Earth by gravity that protects and supports life.
15. The force of air pushing down on Earth.
16. Air pressure decreases as altitude ___.
18. Early Earth was very ...
19. The amount of heat energy in the air molecules is known as ...
20. Once oxygen was produced, this was produced.

1. Early Earth was not protected by a ____ field.
2. Temperature is measured in this degree.
4. Over time, this gas has significantly decreased.
6. The distance above sea level.
9. In general, temperature ____ as altitude increases.
12. There was no oxygen in the atmosphere until these organisms evolved.
14. This has the ability to affect the movement of tropical storms in the Atlantic basin.
17. The primary gas that makes up the modern atmosphere