Question

Soil is made up of a mixture of stones, sand, mud, clay, and decomposed organic material. A soil profile is a vertical section of soil that shows distinct soil layers. In an experiment to study the soil profile, a student adds a handful of soil into a glass jar containing water. Then, the student stirs the soil-water mixture using a glass rod and allows the mixture to settle down for two hours until the water is clear at the top. The student observes that the soil settles in different layers depending on the weight and size of the soil particles as shown.



Resize Columns
Question 23.



Which layer contains organic material in the soil profile?


clay


gravel


humus


stone

Question 24.



Why did the stones settle to form the bottom layer of the soil profile?


They are the heaviest particles.


They have similar colors.


They are the lightest particles.


They have a definite shape.

Answer 1

Question 23: humus

Question 24: They are the heaviest particles.