Name:_____________________________________________________

1. What does the atmosphere protect Earth's surface from?
   
   ____________________________________________________________________________________________________



2. The atmosphere protects living things from:
   
   ____________________________________________________________________________________________________



3. What is air?
   
   ____________________________________________________________________________________________________
   
   
   ____________________________________________________________________________________________________



4. Air's composition is uniform from Earth's surface up to __________________  kilometers.



5. What are the three main gases that make up the atmosphere? (List in order of abundance)
   
   ___________________________     ___________________________     ___________________________



6. Of the five remaining gases, which one is the most important in the heating of our atmosphere?
   
   ____________________________________________________________________________________________________



7. What is the most important variable component of air?
   
   ____________________________________________________________________________________________________



8. What do clouds consist of?
   
   ____________________________________________________________________________________________________
   
   
   ____________________________________________________________________________________________________



9. Name the three reasons why water vapor is important?
   
   
   1. ___________________________________________________________________________________________
   
   
   
   2. ___________________________________________________________________________________________
   
   
   
   3. ___________________________________________________________________________________________



10. What are aerosols?
    
    ____________________________________________________________________________________________________
    
    
    ____________________________________________________________________________________________________



11. Name two natural causes of aerosols.
    
    ____________________________________________________________________________________________________
    
    
    ____________________________________________________________________________________________________



12. Name two human sources of aerosols.
    
    ____________________________________________________________________________________________________
    
    
    ____________________________________________________________________________________________________



13. What do aerosols help to form in the atmosphere?
    
    ____________________________________________________________________________________________________



14. Aerosols can reduce the amount of sunlight reaching Earth's surface by   _____________________________ ,
    
    _____________________________ ,   and    _____________________________   incoming solar energy.