Class 6 Science Separation of Substances: NCERT Solutions for Question 4

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 ___________.

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

What is winnowing? Where is it used?

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?

How do plants and animals help each other in the exchange of gases in the atmosphere?

Can you find a plant in your house or in your neighborhood, which has a long but a weak stem? Write its name. In which category would you classify it?

List five activities that are possible due to the presence of air.

To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.

If a plant has leaves with reticulate venation, what kind of roots will it have?

In which part of a flower, you are likely to find the ovary?

Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not.

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?

How will you prove that air supports burning?

Why does a lump of cotton wool shrink in water?