Science

Soil

Question:

Explain how soil is formed.

Answer:

Soil is formed through the process of weathering. Weathering is a process of physical breakdown and chemical decomposition of rocks and minerals near or at the surface of the earth. This physical and chemical decomposition is primarily done by wind, water, and climate. As a result of these processes, large rock pieces are converted into smaller pieces and eventually to soil.

previuos
next

Soil

Q 1.

Explain how soil pollution and soil erosion could be prevented.

Q 2.

Tick the most suitable answer in question 1 and 2.
In addition to the rock particles, the soil contains
(i) Air and water
(ii) Water and plants
(iii) Minerals, organic matter, air and water
(iv) Water, air and plants

Q 3.

List the differences between clayey soil and sandy soil.

Q 4.

Sketch the cross section of soil and label the various layers.

Q 5.

The water holding capacity is the highest in
(i) Sandy soil
(ii) Clayey soil
(iii) Loamy soil
(iv) Mixture of sand and loam

Q 6.

Match the items in Column I with those in Column II:

Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight
(v) Clayey soil (e) Lesser amount of humus

Q 7.

Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.

Q 8.

Explain how soil pollution and soil erosion could be prevented.

Q 9.

How is clayey soil useful for crops?

Q 10.

Explain how soil is formed.

Q 11.

Solve the following crossword puzzle with the clues given:
ncert-solutions-class-7-science-chapter-9-soil-3
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.

Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.