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