Separation of Substances - Worksheets

CBSE Worksheet-01

Class – VI Science (Separation of Substances)

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1. The method of separation used to separate stone from rice is ___________.
   1. hand picking
   2. threshing
   3. winnowing
   4. filtration
2. The separation of grains from husk is done by the process of ____________.
   1. hand picking
   2. sieving
   3. winnowing
   4. threshing
3. Salt is obtained from sea water mainly by the process of ___________.
   1. decantation
   2. filtration
   3. evaporation
   4. condensation
4. Chalk powder suspension in water can be separated by ___________.
   1. filtration
   2. evaporation
   3. condensation
   4. decantation
5. Match the column

   Column A	Column B
   a. Separating butter from curd	i. Sieving
   b. Separation of husk from grains	ii. Evaporation
   c. Separation of sodium chloride from water	iii. Magnet
   d. Cleaning flour	iv. Churning
   e. Separation of iron particles	v. Winnowing

6. Fill in the blanks:
   1. Pure liquid is obtained from its solution by the process of ________.
   2. Rice grains are separated from common salt by __________.
   3. Tea leaves from tea are separated by __________.
   4. __________ help the clay particles in the suspension to settle down.
   5. Mustard oil is separated from water by ___________.
7. Define: (a) Centrifugation (b) Winnowing
8. How will you separate husk or dirt particles from pulses before cooking?
9. Explain sieving. Is it a good practice to sieve flour before consuming it? Why?
10. Name the method that is used to separate following mixture.
    1. Cream from milk.
    2. Chalk and water
    3. Mud and water
    4. Saw dust and water.

CBSE Worksheet-01
Class – VI Science (Separation of Substances)
Answer key

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1. a
2. c
3. c
4. a
5. (a) – (iv), (b) – (v), (c) – (ii), (d) – (i), (e) – (iii).
6. (a) distillation (b) sieving (c) filtration (d) sedimentation (e) decantation.
7. 1. Centrifugation is defined as the process of separating the components of a mixture by continuously agitating the mixture at a very high speed. For example cream from milk is separated by centrifugation.
   2. Winnowing is the process of separation of the heavier components from the lighter components of a mixture by wind or by blowing air. It is generally used by farmers to separate the lighter impurities such as husk particles from the heavier grains.
8. To separate husk or dirt particles from a given sample of pulses before cooking, we need to wash the pulses with water. Husk or dirt particles being lighter keep floating in water and pulses grain will settle down so we can easily remove them. Then, water with impurities can be removed by decantation.The husk can be separated by winnowing also.
9. The separation method in which mixture is separated, due difference in size particles, using a sieve is called sieving. The smaller particles moves down and larger particle remain in sieve. It is generally used in homes to separate flour from impurities such as pieces of stone, stalk, and husk. It is also used at construction sites to separate sand from small stones.
   No, sieving of flour is not a good practice because it removes the bran that contains protein and starch.
10. Following methods are used to separate the mixture
    1. Churning or Centrifugation
    2. Filtration
    3. Sedimentation and decantation / Filtration.
    4. Filtration.