Name: 
 

Weathering and Soil



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

Decayed organic material turns into a dark colored material called ___________.
a.
litter
c.
humus
b.
clay
d.
soil
 

 2. 

Chemical weathering ____.
a.
is caused by freezing and thawing
b.
breaks apart rocks by physical processes
c.
occurs when chemical reactions dissolve or change the minerals in rocks
d.
none of above
 

 3. 

The rate of weathering depends upon the area's ____.
a.
oxygen
c.
water
b.
climate
d.
soil
 

 4. 

All of the following cause mechanical weathering EXCEPT ____.
a.
ice
c.
burrowing animals
b.
tree roots
d.
carbonic acid
 

 5. 

Each layer of a soil profile is called a __________.
a.
horizon
c.
humus
b.
horizontal
d.
litter
 

 6. 

mc006-1.jpg
Which of these layers would contain the most humus?
a.
A
c.
C
b.
B
d.
all have the same amount
 

 7. 

Mechanical weathering ____.
a.
breaks apart rocks by physical processes
b.
occurs when chemical reactions dissolve or change the minerals in rocks
c.
occurs when iron is exposed to oxygen and water
d.
none of the above
 

 8. 

Soil is a mixture of weathered rock, mineral fragments, water, air and ____.
a.
sand
c.
moss
b.
decayed organic matter
d.
clay
 

 9. 

____ regions are especially vulnerable to erosion because their soils are useful to farmers for only a few years before their nutrients are gone.
a.
Desert
c.
Mountain
b.
Tropical
d.
Prairie
 

 10. 

Chemical weathering is more rapid in a ____ climate.
a.
warm, dry
c.
cold, dry
b.
warm, wet
d.
cold, wet
 

 11. 

Soil is a mixture of __________.
a.
weathered rock and water
c.
mineral fragments
b.
decayed organic matter and oxygen
d.
all of these
 

 12. 

Why is ice wedging most obvious in the mountains?
a.
because the altitude directly contributes to how the water freezes in the cracks of rocks
c.
because the pressure in the mountains allows for the repeated freezing and thawing of water caught in cracks of rocks
b.
because gravity pulls on the water in the cracks more if its found higher in the mountains
d.
because the temperature changes in the mountains allow for the repeated freezing and thawing of water caught in cracks of rocks
 

 13. 

Mechanical weathering is more rapid in a ____ climate.
a.
dry
c.
cold
b.
hot
d.
humid
 

 14. 

When water mixes with carbon dioxide in the air, it forms __________.
a.
sulfuric acid
c.
carbonic acid
b.
hydrochloric acid
d.
ozone
 

 15. 

Minerals found in the B horizon were dissolved in water and carried there by a process called ____.
a.
oxidation
c.
weathering
b.
leaching
d.
littering
 

 16. 

Surface processes that work to break down rock are called__________.
a.
erosion
c.
ice wedging
b.
weathering
d.
oxidation
 

 17. 

Oxidation occurs when materials containing ____ are exposed to oxygen and water.
a.
iron
c.
kaolinite
b.
carbonic acid
d.
all of the above
 

 18. 

The organic matter in humus is made of ____.
a.
dead worms
c.
roots
b.
plant stems
d.
all of the above
 

 19. 

The layer of soil that contains the most organic material is called the ____ horizon.
a.
A
c.
C
b.
B
d.
D
 

 20. 

A soil's composition is dependent on weathering because __________.
a.
it makes the soil more fertile
c.
it keeps the soil moist
b.
it contributes sediment to the soil
d.
it moves the topsoil to other areas where it is more needed
 

 21. 

In areas where freezing and thawing occur frequently, rocks weather rapidly because of the ____
a.
evaporation
c.
leaching
b.
ice breaking the rocks
d.
oxidation
 

 22. 

     
How do chemical and mechanical weathering differ?
a.
Mechanical weathering occurs when rocks are broken by physical processes, and chemical weathering happens when chemical reactions dissolve minerals.
c.
Chemical weathering can occur with the help of water reacting with carbon dioxide, and water has nothing to do with mechanical weathering.
b.
Mechanical and chemical weathering can happen with the help of animals.
d.
Plant roots can help mechanical weathering occur, but have no impact on soil when it comes to chemical weathering.
 

 23. 

Ice wedging is brought about by ____.
a.
carbonic acid freezing on rocks
c.
water freezing and thawing
b.
water and oxygen reacting
d.
rocks colliding with each other
 

 24. 

How does climate affect chemical and mechanical weathering?
a.
Mechanical weathering occurs more rapidly in warm, wet climates, and chemical weathering occurs more in cold climates.
c.
Chemical weathering occurs more rapidly in dry climates and mechanical weathering occurs more in windy climates.
b.
Chemical weathering occurs more rapidly in warm, wet climates, and mechanical weathering occurs more in cold climates.
d.
Chemical and mechanical weathering occur more rapidly in warm, wet climates.
 

 25. 

Litter often covers the ____ horizon.
a.
A
c.
C
b.
B
d.
all of the above
 



 
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