NCERT Solutions Curiosity Chapter 11 .5 Soil, Rocks and Minerals — Activity 11.4: Let us investigate

Book page 218 & 21911 Updated on2026-09-05

Q1.

Collect samples of soils from different areas around your home and school. Guess what could be there in different soils. Observe carefully each soil sample and note its colour. Touch each soil sample and feel its texture. Observe the soil samples with your naked eye. If you have a magnifying lens, look at the soil through it. Record your observations in Table 11.2.

Answer

Collect four or five samples in separate paper packets and label each one. Here is Table 11.2 filled in with typical observations.

Location from which soil sample was collected	What I guessed about the soil	Observation with naked eye (colour and texture)	Observation with magnifying lens
Soil from a farm after ploughing	Soft, dark and moist	Dark brown, loose and crumbly; slightly damp; smells earthy	Fine grains of different sizes, bits of dry root and leaf, a few tiny insects
Soil from the school playground	Hard and dusty	Light brown, hard, packed tight, very little moisture	Mostly sand grains and small pebbles; almost no plant matter
Soil from under a big tree	Full of leaves	Very dark, soft and spongy; cool and damp	Half-rotted leaves, root hairs, ants, a small earthworm
Soil from a river or pond bank	Sticky	Greyish, smooth, sticky when wet; can be rolled into a thread	Very fine particles, few big grains, tiny shells
Sand from a heap or a dry stream bed	Loose and rough	Pale yellow-grey, rough and gritty, runs through the fingers	Separate shiny grains, all roughly the same size

Caution (from the book): Wash your hands thoroughly after touching soil collected from different places. Soil that has garbage in it sometimes carries germs that may be harmful.

Q2.

Is there any difference between your guess and what you can actually observe when you look closely?

Answer

Yes — and that is the whole point of the activity. A guess is made from memory; an observation is made from looking.

What we usually guess	What we actually find
“Soil is just mud”	It contains sand, clay, pebbles, roots, dead leaves, insects and worms
“All soil is brown”	Samples are dark brown, red, grey, black or pale yellow
“Soil has nothing alive in it”	Ants, worms and many organisms too small to see are living in it
“All soils feel the same”	One is gritty, another silky, another sticky

Why guessing first is still useful: in science we always make a guess before we test — the guess tells us what to look for, and the surprise tells us we have learnt something new.

Q3.

Do you see any differences in the soil samples taken from different places?

Answer

Yes — every sample is different in colour, texture and in what it contains.

Colour — farm soil dark brown, forest soil almost black, a river bank grey, and soil in parts of Maharashtra, Chhattisgarh and Tamil Nadu deep red.
Texture — sandy soil is gritty and loose, clayey soil is smooth and sticky, loamy soil is crumbly.
Moisture — forest soil under fallen leaves stays damp; playground soil is dry.
Living things — plenty of worms and insects in garden and forest soil, hardly any in road-side or playground soil.

Why they differ: the soil samples collected from different places may be of different colours because they contain different materials. Soil is formed from the rock lying beneath it, so a different rock gives a different soil. Plants and animals also become part of the soil as they decompose and decay, so places with more plant life have darker, richer soil.

Did you know? There are different types of soil — some are good for growing certain types of plants, while some are good for making bricks for buildings. Forests have a variety of soils, which is why soil is called a precious treasure that supports biodiversity.

Q4.

Do you see differences in what you are able to observe with your naked eye and what you can observe with a magnifying lens?

Answer

Yes — the magnifying lens shows far more than the naked eye.

With the naked eye	With a magnifying lens
Soil looks like one brown powder	Separate grains of many sizes and colours become visible
Only big pebbles and leaves are seen	Tiny bits of dry root, broken leaf and seed coat are seen
No living thing appears	Mites, ants’ eggs and other very small creatures appear
Texture has to be judged by touch	You can actually see whether the grains are round, sharp or flat

Why the lens matters: there may be many small organisms in the soil that we cannot see with our naked eyes at all. A magnifying lens is a scientist’s way of looking harder — the soil has not changed, only our ability to observe it.

Was this helpful? Report an error