Class 6 Science - Chapter Separation of Substances NCERT Solutions | What is winnowing? Where is it used?

True or false?
(a) A mixture of milk and water can be separated by filtration.
(b) A mixture of powdered salt and sugar can be separated by the process of winnowing.                                                                                                                (c) Separation of sugar from tea can be done with filtration.
(d) Grain and husk can be separated with the process of decantation.

Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?

Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving
sugar? In which case would it be possible to dissolve more sugar?

How will you separate sand and water from their mixture?

How would you obtain clear water from a sample of muddy water?

Fill up the blanks
(a) The method of separating seeds of paddy from its stalks is called ___________.
(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of ___________.
(c) Salt is obtained from seawater by the process of ___________.
(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ___________.

What is sieving? Where is it used?

How will you separate husk or dirt particles from a given sample of pulses before cooking.

Why do we need to separate different components of a mixture? Give two examples.

(a) Which kind of garbage is not converted into compost by the redworms?
(b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.

Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?

Do you find that all living beings need the same kind of food?

Name the major nutrients in our food.

Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute

Name five objects which can be made from wood.

Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
(b) Leaves hold the plant upright.
(c) Roots conduct water to the leaves.
(d) The number of petals and sepals in a flower is always equal.
(e) If the sepals of a flower are joined together, its petals are also joined together.
(f) If the petals of a flower are joined together, then the pistil is joined to the petal.

Fill in the blanks:
(a) Joints of the bones help in the ——————— of the body.
(b) A combination of bones and cartilages forms the _______ of the body.
(c) The bones at the elbow are joined by a ______________________ joint.
(d) The contraction of the _____________ pulls the bones during movement.

What is a habitat?

List the common characteristics of the living things.

Explain why the bulb would not glow in the arrangement shown in Fig. 12.13.

Match the items in Column I with one or more items of Column II.

Column I                           Column II
Upper jaw                          have fins on the body
Fish                                    has an outer skeleton
Ribs                                   can fly in the air
Snail                                  is an immovable joint
Cockroach                         protect the heart
                                          shows very slow movement
                                          have a streamlined body

You are given an iron strip. How will you make it into a magnet?

How are cactus adapted to survive in a desert?

Name the major nutrients in our food.

Answer the following:
(a) What is a ball and socket joint?
(b) Which of the skull bones are movable?
(c) Why can our elbow not move backwards?

Explain, why speed is important for survival in the grasslands for animals that live there. (Hint: There are few trees or places for animals to hide in grasslands habitats.)

A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?

Complete the drawing shown in Fig 12.14 to indicate where the free ends of the two wires should be joined to make the bulb glow.