NCERT Class VII Science Solutions: Chapter 9 – Soil Part 5

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Question 19:

In towns and cities, generally, the bore wells have to be dug very deep to get water as compared to bore wells dug in villages.

Give suitable reasons.

Answer:

  1. This is so because of excessive use of water which depletes the ground water.

  2. Towns and cities have asphalted roads and vast areas of soil are concreted. As a result, rain water cannot percolate to recharge ground water and the ground water level further decrease. Villages have larger areas of open soil surface and fewer asphalted roads and concrete surfaces. Thus, larger soil surface area is available for rain water to percolate into the soil easily and recharge the ground water. As a result, even shallow bore wells yield water.

Question 20:

Several terms related to soil are hidden in the squares given as Figure. Spot them and make a list. Two examples are given for you.

Answer:

Humus, Sand, Water, Clay, Gravel, Weathering, Horizon, Percolation, Mineral, Plant, Erosion, Profile.

As showing in images is a crossword puzzle

Crossword Puzzle

As showing in images is a crossword puzzle