“METHODS OF SEPARATION IN EVERYDAY LIFE” : Class 6 : Science
SUMMARY NOTES
Separation is done to remove unwanted substances, obtain useful materials, or purify substances.
Handpicking – used when impurities are large and easily visible (stones from rice).
Threshing – separating grains from stalks after harvesting.
Winnowing – uses wind or air to separate lighter husk from heavier grain.
Sieving – separates particles of different sizes (flour and bran).
Sedimentation – heavier particles settle at the bottom in water.
Decantation – pouring clear liquid after sedimentation.
Filtration – removes insoluble solids using filter paper or cloth.
Evaporation – separates dissolved solids from liquids (salt from seawater).
Distillation – separates liquids with different boiling points.
Condensation – cooling vapour back into liquid.
Magnetic separation – separates magnetic materials (iron) from non-magnetic ones.
Chromatography – separates substances based on different solubility (like colors in ink).
Choice of separation method depends on size, weight, solubility, and state of matter.
SHORT QUESTION AND ANSWER
Q1. What is separation?
A1. Separation is the process of removing unwanted substances from useful materials.
Q2. Why do we need separation in everyday life?
A2. To obtain clean substances, remove impurities, or collect useful parts.
Q3. Give one example of separation at home.
A3. Picking stones from rice.
Q4. Which method is used to separate small stones from rice or pulses?
A4. Handpicking.
Q5. What is threshing?
A5. Threshing is separating grains from stalks.
Q6. How is threshing done?
A6. By beating stalks, trampling under animals, or machines.
Q7. What is winnowing?
A7. Using wind or air to separate husk from grain.
Q8. What property is used in winnowing?
A8. Difference in weight of particles.
Q9. Which method is used by farmers to clean grains?
A9. Winnowing.
Q10. What is sieving?
A10. Sieving is separating particles based on size using a sieve.
Q11. Give one example of sieving.
A11. Separating bran from flour.
Q12. What is sedimentation?
A12. The settling down of heavier particles in a liquid.
Q13. What is decantation?
A13. Pouring the clear liquid after sedimentation.
Q14. Give one example of decantation.
A14. Removing water from soaked rice.
Q15. What is filtration?
A15. Separation of insoluble solids from liquids using filter paper or cloth.
Q16. Give one daily life example of filtration.
A16. Separating tea leaves from tea.
Q17. What is evaporation?
A17. Conversion of liquid into vapour to separate dissolved solids.
Q18. Give one example of evaporation.
A18. Getting salt from seawater.
Q19. What is distillation?
A19. Separation of liquids with different boiling points.
Q20. What is condensation?
A20. Cooling vapour back into liquid.
Q21. Which two processes are used in distillation?
A21. Evaporation and condensation.
Q22. What is magnetic separation?
A22. Using a magnet to separate magnetic material from non-magnetic material.
Q23. Give one example of magnetic separation.
A23. Separating iron filings from sand.
Q24. What is chromatography?
A24. Separation of substances based on solubility in a solvent.
Q25. Where is chromatography used?
A25. To separate colors in ink.
Q26. Which method is used to separate oil from water?
A26. Decantation or using a separating funnel.
Q27. Which method is used to remove husk from paddy?
A27. Winnowing.
Q28. Which method is used to separate cream from milk?
A28. Centrifugation.
Q29. What is centrifugation?
A29. Separation of substances by rapid spinning.
Q30. Which method is used in washing machines?
A30. Centrifugation.
Q31. Which method is used to separate sand from water?
A31. Filtration.
Q32. Which method is used to separate sugar from tea?
A32. Not possible by filtration, as sugar is dissolved.
Q33. Which method is used to separate dissolved sugar from water?
A33. Evaporation.
Q34. Which separation method uses air or wind?
A34. Winnowing.
Q35. Which method is used to separate soluble solids from liquids?
A35. Evaporation.
Q36. Which method is used in water purification plants?
A36. Sedimentation, decantation, and filtration.
Q37. What is the principle of sieving?
A37. Difference in particle size.
Q38. What is the principle of magnetic separation?
A38. Magnetism.
Q39. What is the principle of chromatography?
A39. Different solubility of substances in a solvent.
Q40. Name two separation methods used in the kitchen.
A40. Filtration and evaporation.
LONG QUESTION AND ANSWER
Q1. Why is separation of substances important in our daily life? Explain with examples.
A1. Separation is important to remove harmful or unwanted substances, obtain pure materials, and collect useful components. For example, stones are removed from rice before cooking, salt is obtained from seawater by evaporation, and cream is separated from milk by centrifugation.
Q2. Explain the process of handpicking with two examples.
A2. Handpicking is separating unwanted substances by hand when the quantity is small and impurities are visible. Example: picking stones from rice, or removing spoiled grains from wheat.
Q3. What is threshing? Explain different methods of threshing.
A3. Threshing is separating grains from stalks. Methods:
Beating stalks on the ground.
Trampling under the feet of animals.
Using threshing machines.
Q4. Explain winnowing. Give examples and principle.
A4. Winnowing is separating husk from grain using wind or air. Husk being lighter flies away, while grain falls down. Farmers commonly use this method. The principle is based on difference in weight.
Q5. What is sieving? Write two uses in daily life.
A5. Sieving separates particles based on size using a sieve. Example: removing bran from flour, or separating sand from gravel. The sieve allows smaller particles to pass through while retaining larger ones.
Q6. Explain sedimentation and decantation with examples.
A6. Sedimentation is settling down of heavier particles in water. Example: mud in water settles down. Decantation is pouring clear water after sedimentation, e.g., removing clean water from muddy water.
Q7. Differentiate between decantation and filtration with examples.
A7. Decantation involves pouring clear liquid without disturbing settled particles (e.g., removing water from soaked rice). Filtration involves passing a mixture through filter paper to separate solids (e.g., separating tea leaves from tea).
Q8. Explain filtration with examples and uses.
A8. Filtration separates insoluble solids from liquids using filter paper or cloth. Example: separating tea leaves, filtering muddy water. It is used in water purification and laboratory experiments.
Q9. Explain evaporation with one example.
A9. Evaporation is converting liquid into vapour to separate dissolved solids. Example: salt obtained from seawater after evaporation of water by sunlight.
Q10. Explain distillation with diagrammatic explanation (describe in words).
A10. Distillation separates liquids based on boiling points. The liquid is boiled, vapour collected, and condensed into liquid. Example: separating alcohol from water.
Q11. What is condensation? How is it useful in separation?
A11. Condensation is the process of cooling vapour into liquid. In distillation, vapour is condensed to obtain purified liquid, e.g., distilled water.
Q12. What is magnetic separation? Give two examples.
A12. Magnetic separation uses magnets to separate magnetic substances from non-magnetic ones. Examples: separating iron filings from sand, removing iron pieces from scrap.
Q13. Explain chromatography with an example.
A13. Chromatography separates substances based on solubility. Example: separating colors in ink when filter paper is dipped in water. The colors move at different speeds and separate.
Q14. Explain centrifugation and its uses.
A14. Centrifugation separates substances by spinning at high speed. Example: cream separated from milk. Uses: washing machines, medical labs for blood separation.
Q15. How can oil be separated from water?
A15. Oil is lighter than water. It floats, and can be separated by decantation or separating funnel.
Q16. How is salt obtained from seawater?
A16. Seawater is collected in shallow ponds. The sun heats it, water evaporates, and salt crystals remain. This is an example of evaporation.
Q17. Which methods are used in water purification plants? Explain.
A17. Methods include sedimentation (settling of impurities), decantation (removing clear water), filtration (removing solids), and chlorination (killing germs).
Q18. Explain the principle of sieving, winnowing, and filtration.
A18. Sieving: separation by particle size. Winnowing: separation by weight using wind. Filtration: separation by insolubility using filter medium.
Q19. Which methods are used to separate sand and salt from a mixture? Explain.
A19. Add water to dissolve salt, filter to remove sand, then evaporate water to get salt back.
Q20. Explain the difference between soluble and insoluble substances with examples of separation.
A20. Soluble substances dissolve in water (salt, sugar) – separated by evaporation. Insoluble substances do not dissolve (sand, chalk) – separated by filtration.
Q21. How are husk and paddy separated by farmers?
A21. By winnowing. The husk being lighter flies away in air, while paddy grains fall down.
Q22. Explain with examples where handpicking is not possible and another method must be used.
A22. If quantity is large or impurities are fine, handpicking is not possible. Example: separating husk from wheat – winnowing is used.
Q23. Differentiate between evaporation and distillation.
A23. Evaporation: separates dissolved solids by heating, e.g., salt from seawater. Distillation: separates liquids using evaporation and condensation, e.g., alcohol and water.
Q24. Explain the method of separating cream from milk.
A24. Centrifugation is used. Milk is rotated at high speed, cream being lighter collects at the top, separating from milk.
Q25. Explain how chromatography is useful in real life.
A25. Chromatography separates colors in ink, helps detect impurities in medicines, and separates plant pigments.
Q26. Which methods are used in the kitchen for separation? Explain with examples.
A26. Filtration (tea leaves), sieving (flour), decantation (water from soaked rice), evaporation (thickening milk).
Q27. Explain how decantation and filtration are used together.
A27. First, sedimentation makes heavier particles settle. Decantation removes clear water. Filtration removes remaining fine impurities. Example: purifying muddy water.
Q28. Explain the principle of centrifugation with its applications.
A28. Centrifugation separates substances by density using rapid spinning. Applications: separating cream, drying clothes in washing machines, separating blood components.
Q29. How does separation help in recycling?
A29. Separation methods like magnetic separation and sieving are used to separate waste materials (iron, plastics, glass) for recycling and reuse.
Q30. Explain how different methods of separation are based on physical properties of substances.
A30. Handpicking – size and visibility, Winnowing – weight, Sieving – particle size, Filtration – solubility, Evaporation – boiling, Magnetic separation – magnetism, Chromatography – solubility differences.
MCQS
Which method is used to remove stones from rice?
a) Threshing
b) Winnowing
c) Handpicking
d) Filtration
Answer: c) Handpicking
Threshing is done to separate:
a) Stones from grains
b) Husk from grains
c) Grains from stalks
d) Salt from water
Answer: c) Grains from stalks
Winnowing is based on difference in:
a) Size
b) Weight
c) Colour
d) Taste
Answer: b) Weight
Sieving is used to separate substances of different:
a) Colours
b) Sizes
c) Shapes
d) Solubility
Answer: b) Sizes
Filtration is useful for separating:
a) Salt and water
b) Sand and water
c) Husk and grains
d) Oil and water
Answer: b) Sand and water
Sedimentation involves:
a) Mixing of substances
b) Heating the solution
c) Heavier particles settling at bottom
d) Vapour formation
Answer: c) Heavier particles settling at bottom
Decantation follows which process?
a) Winnowing
b) Sedimentation
c) Evaporation
d) Sieving
Answer: b) Sedimentation
Evaporation is used to obtain:
a) Rice from stones
b) Salt from seawater
c) Oil from water
d) Tea from leaves
Answer: b) Salt from seawater
Which method is used in making tea?
a) Winnowing
b) Sieving
c) Filtration
d) Evaporation
Answer: c) Filtration
In distillation, the separated liquid is collected after:
a) Evaporation
b) Condensation
c) Freezing
d) Mixing
Answer: b) Condensation
Oil and water can be separated by:
a) Handpicking
b) Decantation
c) Filtration
d) Evaporation
Answer: b) Decantation
Which method is used to separate mud from muddy water?
a) Filtration
b) Sedimentation and decantation
c) Winnowing
d) Sieving
Answer: b) Sedimentation and decantation
Husk is separated from wheat grains using:
a) Handpicking
b) Winnowing
c) Sieving
d) Filtration
Answer: b) Winnowing
The method to separate bran from flour is:
a) Sieving
b) Winnowing
c) Filtration
d) Threshing
Answer: a) Sieving
Common salt from seawater is obtained by:
a) Filtration
b) Distillation
c) Evaporation
d) Sieving
Answer: c) Evaporation
Which separation method is used in water purifiers?
a) Threshing
b) Filtration
c) Winnowing
d) Evaporation
Answer: b) Filtration
Filtration cannot separate:
a) Sand and water
b) Tea leaves from tea
c) Oil and water
d) Chalk and water
Answer: c) Oil and water
In handpicking, the condition is:
a) The substance must be liquid
b) Impurities must be small and invisible
c) Impurities must be large and visible
d) Substances must be soluble
Answer: c) Impurities must be large and visible
Which method uses wind for separation?
a) Winnowing
b) Sieving
c) Filtration
d) Distillation
Answer: a) Winnowing
Which process is used in making jaggery from sugarcane juice?
a) Sieving
b) Evaporation
c) Filtration
d) Decantation
Answer: b) Evaporation
The clear liquid poured after sedimentation is called:
a) Filtrate
b) Mixture
c) Residue
d) Solution
Answer: a) Filtrate
Mixtures of two immiscible liquids are separated by:
a) Sieving
b) Filtration
c) Decantation
d) Distillation
Answer: c) Decantation
Separation of butter from milk is done by:
a) Winnowing
b) Filtration
c) Churning
d) Evaporation
Answer: c) Churning
Which separation method is used in washing machines?
a) Distillation
b) Winnowing
c) Filtration
d) Centrifugation
Answer: d) Centrifugation
Which of these is a method of separation used in dairies?
a) Churning
b) Sieving
c) Winnowing
d) Handpicking
Answer: a) Churning
Which process is used in rain formation in the water cycle?
a) Sedimentation
b) Condensation
c) Filtration
d) Decantation
Answer: b) Condensation
Which separation method is used to purify drinking water in cities?
a) Winnowing
b) Evaporation
c) Filtration and sedimentation
d) Threshing
Answer: c) Filtration and sedimentation
The residue left on filter paper is called:
a) Solution
b) Filtrate
c) Sediment
d) Solvent
Answer: c) Sediment
Which of the following separates tea leaves from tea?
a) Sieving
b) Filtration
c) Winnowing
d) Evaporation
Answer: b) Filtration
Evaporation changes a liquid into:
a) Ice
b) Solid
c) Vapour
d) Sediment
Answer: c) Vapour
Distillation is mainly used to separate:
a) Solid-solid mixtures
b) Liquid-liquid mixtures
c) Solid-liquid mixtures
d) Gas-liquid mixtures
Answer: b) Liquid-liquid mixtures
Which of the following cannot be separated by sieving?
a) Flour and bran
b) Rice and stones
c) Sand and pebbles
d) Gravel and sand
Answer: b) Rice and stones
Which process helps to remove insoluble impurities from water?
a) Filtration
b) Distillation
c) Evaporation
d) Churning
Answer: a) Filtration
Butter is separated from curd by:
a) Handpicking
b) Churning
c) Sedimentation
d) Filtration
Answer: b) Churning
What is the principle of winnowing?
a) Density difference
b) Size difference
c) Shape difference
d) Colour difference
Answer: a) Density difference
