Question

class 7 science ch 9 activity 9.2 solution​

Answer 1

Answer:

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Explanation:

class 7 science ch 9 activity 9.2 solution

Answer 2

Answer:

Ques 1: Do you see layers of particles of different sizes in the glass tumbler?

Ans 1: We can see layers of particles of different sizes in the glass tumbler. There is a topmost layer of some dead rotting leaves or animal remains floating on water. This rotting dead matter in the soil is called humus. Below the layer of humus, there is a clear water level which contains dissolved part from the soil. Below water layer, there are layers of clay, sand, gravel and stones.

Ques 2: Draw a diagram showing these layers.

Ans 2: [In attachment]

Ques 3: Are there some dead rotting leaves or animal remains floating on water?

Ans 3: The dark black upper layer of the soil is known as humus. It is the dead remains of plants and animals that have been decomposed by bacteria and fungi. This humus-rich soil increases the aeration capacity of soil and also helps in the penetration of roots of plants. The decomposition of organic matter helps in bringing the plant and animal residues back to the soil.