Question 1
What purpose does handpicking serve in separation? (i) Filtration (ii) Sorting (iii) Evaporation (iv) Decantation.
Steps only
(ii) Sorting.
Answer
(ii) Sorting.
CLASS 6 · SCIENCE · CHAPTER 9
Methods of Separation in Everyday Life
Simple answers to all 10 end questions, with clear examples for the chapter’s everyday separation activities and prompts.
30 worked answersComplete chapter answers
30 worked answers · short steps first, explanations when you need them
Let us enhance our learning
Textbook pages 161–162
Question 2
Which substances are commonly separated using churning? (i) Oil from water (ii) Sand from water (iii) Cream from milk (iv) Oxygen from air.
Steps only
(iii) Cream from milk.
Answer
(iii) Cream from milk.
Question 3
Which factor is usually essential for filtration? (i) Apparatus size (ii) Presence of air (iii) Pore size (iv) Temperature of mixture.
Steps only
(iii) Pore size.
Answer
(iii) Pore size.
Question 4
Mark each statement True or False, give a reason, and correct any false statement: (i) Salt can be separated from salt solution by leaving it in the Sun. (ii) Handpicking should be used only when one component is present in a small amount. (iii) Puffed rice and rice grains can be separated by threshing. (iv) Mustard oil and lemon water can be separated by decantation. (v) Sieving separates rice flour from water.
Steps only
(i) T (ii) T (iii) F—use winnowing (iv) T (v) F—use filtration.
Answer
- (i) True.
- (ii) True.
- (iii) False: winnowing can separate puffed rice from heavier rice grains.
- (iv) True.
- (v) False: use filtration to separate rice flour from water.
Question 5
Match: (i) gram flour and black gram (ii) chalk powder and water (iii) corn and potatoes (iv) iron powder and sawdust (v) oil and water. Methods: (a) handpicking (b) magnetic separation (c) decantation (d) sieving (e) filtration.
Steps only
(i) d (ii) e (iii) a (iv) b (v) c.
Answer
- (i) d
- (ii) e
- (iii) a
- (iv) b
- (v) c.
Question 6
When would you use decantation instead of filtration to separate a solid from a liquid?
Steps only
Use decantation after a heavy insoluble solid settles; use filtration for finer particles.
Answer
Use decantation when a heavy insoluble solid has settled at the bottom and the clearer liquid can be poured off. Use filtration for finer particles or when the solid does not settle easily.
Question 7
Can you relate nasal hair to a separation process?
Steps only
Nasal hairs filter some dust from inhaled air.
Answer
Nasal hairs act like a simple filter by trapping some dust from the air we breathe.
Question 8
What are masks generally made of, and what is their role?
Steps only
Layered fabric filters some droplets and particles; cover the nose and mouth.
Answer
Masks are commonly made from layers of non-woven fabric or cloth. They help filter droplets and particles from air moving through them, reducing spread when worn correctly over the nose and mouth.
Question 9
Describe steps to separate potatoes, salt, and sawdust from a mixture.
Steps only
Handpick potatoes → dissolve salt in water → filter out sawdust → evaporate water to get salt.
Answer
1. Handpick the potatoes. 2. Add water so the salt dissolves. 3. Filter: sawdust stays on the filter and salt solution passes through. 4. Evaporate the water to obtain salt.
Question 10
Choose the correct words to complete the story, then give it a title: Leela was working in a farm with her father when she realised they left their drinking water at home. Before her father felt thirsty/hungry, she went to a nearby pond to fetch water/grains. The water was muddy and fit/unfit for drinking. She let it settle and then filtered/churned it using paper/muslin cloth. She boiled/cooled it for about 10 minutes in a covered pan. After cooling/boiling, she filtered/churned it again and made it fit/unfit for drinking.
Steps only
thirsty, water, unfit, filtered, muslin, boiled, cooling, fit. Title: “Leela Makes Water Safer”.
Answer
Correct choices: thirsty; water; unfit; filtered; muslin cloth; boiled; cooling; fit. Suitable title: “Leela Makes Water Safer”. Settling and filtering remove many particles, and boiling helps make water safer from germs.
Chapter Questions and Activities
Textbook pages 143–160, 162
Question Prompt 1
Why do people separate stones or husk from grains?
Steps only
To remove unwanted material and clean the grains.
Answer
They remove unwanted matter so the grains are clean and suitable for use.
Question Prompt 2
When is handpicking a suitable method?
Steps only
When unwanted pieces are few and easy to see and pick.
Answer
Handpicking works when unwanted pieces are few, visible, and easy to remove by hand.
Question Activity 9.1
What happens when roasted peanuts are rubbed and then blown gently?
Steps only
Light skins blow away; heavier peanuts fall nearby.
Answer
The lighter peanut skins are blown farther away while the heavier peanuts fall nearby. This is winnowing.
Question Prompt 3
How could a small mixture of puffed rice and chana dal be separated without handpicking?
Steps only
Winnow: puffed rice blows farther; heavier chana dal falls closer.
Answer
Use gentle winnowing. The lighter puffed rice is carried farther by air; the heavier chana dal falls closer.
Question Prompt 4
What is threshing?
Steps only
Separating grains from stalks by beating or a machine.
Answer
Threshing is separating grains from harvested stalks by beating or using a thresher.
Question Prompt 5
How can Valli separate husk from rice in a closed room without wind?
Steps only
Create airflow with a fan; husk blows away and grains fall down.
Answer
Use a hand fan or another safe source of moving air to winnow. The lighter husk blows away while the rice grains fall close by.
Question Prompt 6
How does sieving separate flour and bran?
Steps only
Fine particles pass; larger particles stay on the sieve.
Answer
Fine flour passes through the sieve; larger bran remains on it. The holes must be smaller than the pieces to be held back.
Question Prompt 7
How is common salt obtained from seawater?
Steps only
Evaporate seawater in shallow pans, then collect and purify the salt.
Answer
Seawater is left in shallow pans so the water evaporates. The solid salts remain and common salt is purified from them.
Question Prompt 8
Why can white patches appear on dark clothes after sweating in hot weather?
Steps only
Sweat water evaporates and leaves salt on the fabric.
Answer
Water in sweat evaporates, leaving dissolved salts behind as white patches.
Question Activity 9.3
What remains when salt solution is heated until the water evaporates?
Steps only
Salt remains after water evaporates; heat only under supervision.
Answer
Salt remains in the dish after the water evaporates. Heat this only with teacher/adult supervision.
Question Prompt 9
How can tea leaves be removed from tea? Compare settling, decantation, and filtration.
Steps only
Sedimentation then decantation works partly; a strainer filters leaves out.
Answer
Letting leaves settle is sedimentation; pouring off the tea is decantation. A strainer filters out the remaining leaves more effectively.
Question Prompt 10
Which method can separate oil from water?
Steps only
Let layers form, then use decantation.
Answer
Decantation can separate the layers because oil and water are immiscible.
Question Activity 9.4
What do you observe when muddy water passes through filter paper?
Steps only
Mud is residue; water is filtrate, which may still need treatment.
Answer
Mud stays on the filter paper as residue; water passes through as filtrate. Filtered water is not automatically safe to drink.
Question Activity 9.5
Suggest a low-cost model to filter visible dirt from pond water.
Steps only
Layer cloth, gravel, and sand to remove particles; filter water still needs disinfection.
Answer
A bottle with clean cloth, washed gravel, sand, and charcoal can filter some visible dirt. The filtered water still needs proper disinfection before drinking.
Question Prompt 11
How is catching fish with a net similar to filtration?
Steps only
Water passes through the net; fish are trapped.
Answer
A net lets water pass but traps fish too large to pass through, like a filter trapping larger particles.
Question Prompt 12
How can sour milk be used, and what separation method can help?
Steps only
Strain curds from whey through muslin; check safety with an adult.
Answer
If an adult confirms it is safe, curds can be separated from whey by straining through clean muslin (filtration). Do not use milk that may be unsafe.
Question Prompt 13
What does churning do when making butter from curd?
Steps only
Churning separates butter from buttermilk.
Answer
Churning separates butter from curd or cream; butter collects separately and buttermilk remains.
Question Prompt 14
How can iron nails be separated from sawdust?
Steps only
Use a magnet; iron is attracted, sawdust is not.
Answer
Use a magnet to attract and remove the iron nails. This is magnetic separation.
Question Prompt 15
Choose a suitable method for each: stones from pulses; butter from curd; chillies from cooked food; watermelon seeds; sawdust and nails; marigolds from flowers; pebbles from sand; coconut pieces from rice flour; oil from water; salt from salt solution.
Steps only
Handpicking: stones, chillies, seeds, flowers, coconut; churning: butter; magnet: nails; sieve: pebbles; decant: oil/water; evaporate: salt solution.
Answer
Possible matches: stones/pulses—handpicking; butter/curd—churning; chillies/food—handpicking; watermelon seeds—handpicking; nails/sawdust—magnetic separation; flowers—handpicking; pebbles/sand—sieving; coconut/rice flour—sieving or handpicking; oil/water—decantation; salt solution—evaporation.
Question Learning further
Which separation methods might be used to prepare herbal kadha?
Steps only
Extract by boiling, then filter/strain out the herbs.
Answer
Boil herbs in water to extract their soluble contents, then strain the solid leaves out by filtration.