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.
(a) False
No, both are miscible components and make a homogeneous mixture. So we cannot separate them by filtration.
(b) False
We cannot separate them by winnowing method because in powdered form they both will make a homogenous mixture.
(c) True
Yes, it is so because by filtration the larger particles of sugar can be separated whereas the solution of tea can pass through it easily.
(d) False
No, because decantation method is used for two immiscible components. This can be done by winnowing.
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.
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?
The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?
A magnet was brought from different directions towards a toy boat that has been floating in water in a tub. Affect observed in each case is stated in Column I. Possible reasons for the observed affects are mentioned in Column II. Match the statements given in Column I with those in Column II.
Column I Column II
Boat gets attracted towards the magnet Boat is fitted with a magnet with north pole towards its head
Boat is not affected by the magnet Boat is fitted with a magnet with south pole towards its head
Boat moves towards the magnet if north Boat has a small magnet fixed along its length
pole of the magnet is brought near its
head
Boat moves away from the magnet Boat is made of magnetic material when north pole is brought near its head
Boat floats without changing its direction Boat is made up non-magnetic material
When does a drought occur?
List five activities that are possible due to the presence of air.
Give two examples of periodic motion.
Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.
How is a compass used to find directions?
How are clouds formed?
The component of air used by green plants to make their food, is ___________.