NCERT Solutions for Class 6 Science Chapter 9 Methods of Separation in Everyday Life (PDF) – 2027

Yes. I keep in touch with my grandparents, relatives and friends by phone and video calls, by visiting them in the holidays and on festivals, and by sending messages, letters and small gifts.

In Haryana and Punjab, farmers sing boliyan at the wheat harvest and on Baisakhi. I asked my grandmother for a harvest song, wrote its words in my notebook and sang it with my friends, clapping to the beat. Such work songs keep everyone in the same rhythm, so the work feels less tiring.

The thin, papery red-brown skin comes off the peanuts. We are left with a mixture of peanut seeds (heavier) and loose skins (very light).

Yes. The skins can be picked out by hand, but the easiest way is to blow air over the mixture. The light skins fly away and the heavier peanuts stay behind.

The papery skins fly away with the puff of air and float down some distance away. The peanut seeds stay in your palm, hardly moving.

The removed peanut skins are blown away; the peanuts are not, because the skins are much lighter than the peanuts.

Yes — by winnowing (blowing air). Put the mixture in a soop or a plate and toss it gently in front of a fan or in the breeze. The light puffed rice is blown away, while the heavier chana dal falls back into the tray.

Farmers separate the grains from the husk by winnowing. Standing on a raised platform, the farmer lets the threshed wheat fall slowly from a soop (bamboo tray) in the direction of the wind. The heavier grains fall close by in a heap, while the lighter husk is blown away and forms a separate heap.

No, they do not fall at the same place. The husk is blown away and lands far off; the grains fall close to the farmer’s feet. Yes, the wind can separate the two components — that is exactly what the figure shows.

Yes. At home, rice or dal is cleaned in a soop or a flat plate. It is tossed up and down near an open window or under a fan, so the light husk and dust fly off while the heavier grains fall back into the tray. We also blow away the skins of roasted peanuts or chana. Both are winnowing.

Winnowing needs moving air, and a closed room has none. Valli can switch on a fan and let the mixture fall slowly in front of it, blow on it, or open a window or door. The moving air carries the lighter husk away, while the heavier rice falls into the tray.

(i) Yes. In a sieve all the holes are of about the same size.
(ii) No. If the holes are larger than all the substances, everything falls through and nothing is separated.
(iii) Yes. The particles that pass through are smaller than the holes (fine flour); those that remain on the sieve are bigger (bran, small stones).

Yes. At building sites, workers throw sand on a large sloping wire-mesh sieve. The fine sand passes through the holes, while pebbles and stones, which are bigger than the holes, stay back and slide down in front. The sieved sand is used for smooth plaster.

Sabarmati Ashram in Ahmedabad was Mahatma Gandhi’s home (1917–1930). It is famous as the starting point of the Dandi March (Namak Satyagrah) on 12 March 1930.

Why it was organised: the British taxed salt and did not allow Indians to make their own salt. Gandhiji and his companions walked about 385 km to Dandi on the sea coast and on 6 April 1930 picked up natural salt, peacefully breaking this unjust law.

Poster (sample): Gandhiji leading marchers from Sabarmati to the sea at Dandi, titled “Namak Satyagrah, 1930”.

Common salt is mainly obtained from seawater. Seawater is kept in shallow pits and exposed to sunlight and air. In a few days the water evaporates, leaving behind a solid mixture of salts; common salt is obtained from it by further purification. Salt is also obtained from salt lakes and rock-salt mines.

Besides the sea, common salt is found in these water bodies of India:

Yes, white patches appear on the paper where the drops were. The patches are salt left behind — we can feel it by touching the paper. The water has evaporated: it changed into water vapour and went into the air.

Yes. In hot summers we sweat a lot, and sweat is water with salt dissolved in it. When the sweat dries, the water evaporates but the salt does not, so the salt is left on the cloth as white patches. They show up clearly on dark clothes.

The water boils away as vapour. When the dish cools, a layer of white solid salt is left in the china dish. Yes, we get the salt back. This is separation by evaporation.

Yes. In the figure, water is heated in a kettle; the steam touches a cool lid held above it, turns back into water drops and drips into the glass. If salt water is heated like this, the salt stays in the kettle and pure water collects in the glass. The processes are evaporation followed by condensation.

(i) By filtration: pour the tea through a tea strainer; the leaves stay in the strainer.
(ii) Without a strainer, by sedimentation and decantation: leave the pan undisturbed so the leaves settle at the bottom, then gently tilt it and pour the tea into a cup.

Decantation. Leave the mixture undisturbed until the oil forms a separate layer on top of the water. Then gently tilt the vessel and pour the oil layer into another container, leaving the water behind.

No, not properly. A tea strainer has large holes. It removes only big bits like leaves and twigs; the fine mud particles pass through, so the water stays muddy. A folded cloth or a filter paper, which has much finer pores, is needed.

A piece of cloth has very small holes (pores) between its woven threads. These pores are much finer than the holes of a tea strainer, so the cloth works as a filter: it holds back mud particles and lets the water pass. Cloth is also cheap and available in every home.

There is no fixed number — it depends on how muddy the water is and how fine the cloth is. Usually 3–4 layers of clean cotton or muslin cloth give much clearer water than one layer, because each extra layer traps particles that slipped through the layer before it.

How to fold it — four steps, exactly as in Fig. 9.10:

1. Start with a round filter paper lying flat.
2. One fold — fold it exactly in half. You now have a half-circle.
3. Two folds — fold the half-circle in half again. You now have a quarter-circle.
4. Cone — open the quarter out so that three layers lie on one side and one layer on the other. It opens into a cone that sits neatly inside the funnel.

No, the mud particles do not pass through. They are held back on the filter paper. The water that trickles out of the funnel into the conical flask is clear.

Sample answer — a bottle filter: Cut the bottom off a plastic bottle and turn it upside down over a glass. Tie a cotton cloth over its mouth. Fill it from the bottom up with cotton, charcoal powder, fine sand, coarse sand and pebbles. Pour the pond water in at the top; clearer water collects in the glass. (Boil it before drinking.)

Sample answer — lines to fill the blanks:

(after “…Mama fish has tears.”)
Bags and bottles choke our river home,
Wrappers and straws float far and near.
(after “…hears mother’s sorrow,”)
Keep waste out of water, and let little fish grow.
(at the end)
Keep them clean, and life will run its course.

Sour (split) milk can be used to make paneer (chhena). Pour it into a muslin cloth: the solid chhena stays in the cloth and the liquid (whey) drains out. The method of separation used is filtration. Sour milk can also be used in kadhi, dhokla or batters.

An electric mixer–grinder (mixie), or an electric hand blender (churner). It churns the curd fast, so the lighter butter separates and floats, leaving buttermilk (chhach) behind.

Magnetic separation. The magnet attracts the iron nails (a magnetic substance) and pulls them out of the sawdust, which is non-magnetic and stays behind.

Basket A — to remove a component that is not useful: slips 1, 3, 4.
Basket B — to separate two different but useful components: slips 2, 5, 6, 7, 8, 9, 10.

The matching pairs (Tank 1 → Tank 2) are:

Answer: (ii) Sorting. In handpicking we sort out unwanted pieces, such as small stones from grains, by hand on the basis of differences in size, colour and shape.

Answer: (iii) Cream from milk. Churning makes the lighter fat (cream or butter) separate from the rest of the milk and float on top.

Answer: (iii) Pore size. A filter holds back only particles that are bigger than its pores; smaller particles pass through with the liquid.

Corrected false statements:

• (iii) A mixture of puffed rice and rice grains can be separated by winnowing (the light puffed rice is blown away) or by sieving, since the two differ in weight and in size.
• (v) Filtration is used to separate a mixture of rice flour and water, because rice flour is insoluble in water and is held back on the filter.

We use decantation instead of filtration when:

• the solid is heavy and insoluble and settles quickly (tea leaves, sand, mud);
• a large amount of liquid must be separated quickly, or no filter is available;
• there is so much solid that it would choke the filter — we settle and decant first, then filter;
• the mixture is of two liquids that do not mix, such as oil and water.

Yes — filtration. The hairs in our nose act like a filter. They trap dust, pollen and smoke particles from the air we breathe in, and let cleaner air pass on to the lungs.

Material: masks are generally made of layers of cloth (cotton) or of non-woven synthetic fabric (surgical and N95 masks).

Role: a mask works as a filter. It traps the tiny droplets carrying the virus when we cough, sneeze or speak, and stops droplets, dust and germs in the air from entering our nose and mouth.

Use one method at each step:

Correct options, in order: thirsty, water, unfit, filtered, muslin cloth, boiled, boiling, filtered, fit.
Title: “Leela Makes the Water Safe”.

While making tulsi kadha we use handpicking (choosing good tulsi leaves and removing stalks and dirt) and filtration (straining the boiled kadha through a tea strainer or muslin cloth). We may also let it stand so the bits settle (sedimentation) and pour off the clear kadha (decantation).

Sample answer (opening scene):
Narrator: First stop — Nani’s house in Haryana.
Valli: Nani, why are you picking stones out of the grain?
Nani: So that it is fit for cooking. Picking by hand is called handpicking.
Mama: For the husk we use the wind — that is winnowing.

Next scenes: Ahmedabad (evaporation — salt from seawater), Puducherry (sedimentation, decantation, filtration), Bhopal (churning) and Shillong (magnetic separation).

In one week I noticed handpicking (stones from dal), sieving (bran from atta), filtration (tea leaves from tea), decantation (water poured off washed rice), churning (butter from curd) and evaporation (puddles drying up). Handpicking and sieving were used most, because most kitchen mixtures are solids of different sizes.

Sample answer (case study): The ragpicker sorts waste mainly by handpicking — paper, plastic, glass, metal and cloth go into separate bags by looking at and feeling them. Some use a magnet to pull out iron scraps (magnetic separation) and shake waste through a sieve to remove dust. This sorting is the first step of recycling.

We also told families nearby about the neighbourhood school, so that children below 14 join it.

(i) Collect clippings on harvesting (threshing and winnowing by threshers and combine harvesters), sand screening at building sites (sieving), water treatment plants (sedimentation, filtration) and salt making (evaporation). Paste them in a scrapbook and write the method under each.
(ii) Ask farmers: How do you thresh and winnow now? Do you use a thresher or a combine harvester? How do you clean the grain before selling it?

Six components — so use one property at a time, and always take out the easiest first. Here is the full sequence.