ch.6 vocabulary

Question 1

weathering

Answer 1

mechanical or chemical process that breaks down rocks into smaller and smaller fragments

Question 2

mechanical weathering

Answer 2

physical process that breaks rocks apart without changing their chemical composition; can be caused by growing plants, lighting, expanding ice, and expansion and contraction that occurs when an area heats and cools

Question 3

ice wedging

Answer 3

mechanical weathering process that occurs when water freezes in the cracks of rocks and expands, breaking the rocks apart

Question 4

chemical weathering

Answer 4

type of weathering, that occurs when air, water, and other substances react with minerals in rocks

Question 5

oxidation

Answer 5

chemical weathering process that occurs when a material such as iron is exposed to oxygen and water; causes the iron in rock to rust and turn reddish

Question 6

climate

Answer 6

pattern of weather that occurs in a particular area over many years

Question 7

soil

Answer 7

material that supports vegetation and is a mixture of weathered rock, mineral fragment, organic matter, water, and air; may take thousands of years to form

Question 8

humus

Answer 8

dark-colored, decayed organic matter in soil that serves as a nutrient source for plants, promotes good soil structure, and helps soil hold water

Question 9

soil profile

Answer 9

vertical section of soil layers

Question 10

horizon

Answer 10

a soil layer in the soil profile; most areas have three-the A horizon(top layer), the B horizon(middle layer),the C horizon(bottom layer)

Question 11

litter

Answer 11

leaves, twigs, and other organic matter in the horizon A that changes to humus when it is exposed to decomposing organic organisms

Question 12

leaching

Answer 12

removal of minerals that have been dissolved in water