Weathering and Soil

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 Rain

Weathering and Soil