Weathering and Soil Test Review. Question 1 True or False: After chemical weathering, the chemical make up of the rock is the same. False.

Weathering and Soil

Test Review

Question 1

• True or False: After chemical weathering, the chemical make up of the rock is the same.

• False

Question 2

• Which soil layer contains partially weathered rock?

• C Horizon

Question 3

• What is the loose material on the Earth’s surface that contains humus?

• Soil

Question 4

• Which soil layer is the best for growing plants?

• The A Horizon (Topsoil)

Question 5

• What agent of mechanical weathering wears away rock by the grinding action of other rock particles?

• Abrasion

Question 6

• How does ice wedging cause mechanical weathering of rocks?

• By freezing and thawing

Question 7

• The growth of plant roots and animal activity is what type of weathering?

• Mechanical Weathering

Question 8

• What kind of weathering causes the mineral composition of rocks to change?

• Chemical weathering

Question 9

• A rock containing iron becomes soft and crumbly and reddish-brown in color. It has probably been weathered by what?

• Oxygen (oxidation)

Question 10

• How does a hot and wet climate affect the rate of weathering?

• It makes it take place faster

Question 11

• What are the most important factors in determining the weathering rate of rocks?

• Climate and mineral composition

Question 12

• Why do permeable rocks weather easily?

• Because they are full of tiny connected air spaces

Question 13

• How does soil formation begin?

• With the weathering of rock

Question 14

• What is the mixture of rock particles, minerals, decayed organic material, water, and air called?

• Soil

Question 15

• What is the decayed organic material in soil called?

• Humus

Question 16

• Removing nutrients such as iron and copper from the ground is called what?

• Depletion

Question 17

• Which soil particle is the largest?

• Gravel

Question 18

• What soil particle is the smallest?

• Clay

Question 19

• The type of soil called loam is made of what?

• Nearly equal amounts of sand, silt, and clay

Question 20

• In which layer of soil is topsoil found?

• A Horizon

Question 21

• What type of particles does the B Horizon contain?

• Clay, minerals, and a little humus

Question 22

• What do living organisms do in the soil?

• Mix the soil and make humus

Question 23

• What do decomposers do in soil?

• Break down and digest the remains of dead organisms

Question 24

• Which organism does most of the work of mixing humus into the soil?

• Earthworms

Question 25

• What can cause the loss of soil that is not protected by plant cover?

• Erosion by wind or water

Question 26

• Plowing removed the grass from the Great Plains and exposed the soil. What effect did this have when a drought struck the Great Plains during the 1930’s?

• It helped to cause the Dust Bowl

Question 27

• Using land to grow food crops is an example of what?

• Agriculture

Question 28

• What is the solid layer of rock beneath the soil called?

• The Bedrock (R Horizon)

Question 29

• What is another name for the B Horizon?

• Subsoil

Question 30

• What type of weathering occurs when pollutants in the air mix with the water vapor in the air?

• Acid Precipitation