Cell is a basic unit of all living things Life processes

Solar energy is energy from the sun

A solar collector is a device that collects sunlights and changes it to

heat energy

12. 
    A device called a solar cell changes solar energy into electrical energy
    
13. 
    In a hydroelectric power plant the energy of moving water turns turbines
    

attached to generators that produce electricity

14. 
    Daily movements of the water level along the shore are called tides
    
15. 
    Tidal energy is the energy of rising and falling tides
    
16. 
    Geothermal energy source is deep inside the earth
    
17. 
    Melted rock inside the earth is called magma
    
18. 
    Hot spots are areas of geothermal energy
    
19. 
    Plant and animal matter is called biomass
    
20. 
    Process of changing biomass into usable energy is called bioconversion
    

CHAPTER 9

1. 
   Weathering is all the processes that break rock into small pieces
   
2. 
   Physical weathering is all the processes that break apart rock without
   

changing its chemical makeup

3. 
   The daily freezing and melting of water causes large rocks to break up into
   

smaller pieces. This kind of physical weathering is called frost action

4. 
   Chemical weathering is all the processes that break apart rock by changing
   

its chemical makeup

5. 
   The movement of weathered rock and soil from one place to another is
   

called erosion

6. 
   Water, ice and wind are called the agents of erosion
   
7. 
   Some of water from rain melting snow flows over the earth’s surface.
   

This water called runoff

8. 
   The downward cutting of a riverbed can create a deep valley with steep side.
   

Such a valley is called a canyon

9.