Unit 5 Soil

What is mechanical weathering?
Occurs when physical forces break rock into smaller and smaller pieces without changing the rock’s mineral composition.
What is frost wedging?
Is a most common in mountainous regions in the middle latitudes.
When water freezes,its volume….
It expands by about 9 percent,exerting a tremendous outward force.
Which of the following is NOT associated with mechanical weathering?
Reactions with oxygen
What is chemical weathering?
Is a transformation of rock into one or more new compounds.
Which of the following is the result of chemical weathering?
A rock that has been broken into tiny pieces.
The atmospheric gas that form a mild acid when dissolved in water is….
Carbonic acid
What would cause the inscription on a marble gravestone to become harder and harder to read over time?
SWEAT
What climate does chemical weather favor the most?
Water
What are the major components of soil?
Soil has four major components mineral matter,or broken-down rock;organic matter,or humus,which is the decayed remains of organisms;water;and air.
A soil texture is determined by….
Soil texture refers to the proportions of different particle sizes.
The main source of organic matter in soil is….
Water
Use Figure 5-1 to determine what a soil is called if it has 20 percent clay,60 percent silt,and 20 percent sand….
Clay loam
What are the proportions of clay,silt,and sand shown at point B in Figure 5-1?
Clay 20 percent,Silt 40 percent,and Sand at 40 percent.
What are the proportions of clay,silt,and sand shown at point A in Figure 5-1?
Clay 60 percent,Silt 20 percent,and Sand at 80 percent.
What are the proportions of clay,silt,and sand shown at point C in
Figure 5-1?
A soil associated with hot and wet tropics is….
Pedalfer soils contain high amounts of….