Lesson.3 Matter around us
Lesson.3 Matter around us
I. Choose the correct answer:
1. _________ is not made of matter
- gold ring
- iron nail
- light ray
- oil drop
Ans : light ray
2. 200 ml of water is poured into a bowl of 400ml capacity. The volume of water now will be _________
- 400 ml
- 600 ml
- 200 ml
- 800 ml
Ans : 200 ml
3. Seeds from water-melon can be removed by _________
- hand-picking
- filtration
- magnetic separation
- decantation
Ans : hand – picking
4. Lighter impurities like dust when mixed with rice or pulses can be removed by _________
- filtration
- sedimentation
- decantation
- winnowing
Ans : decantation
5. _________ is essential to perform winnowing activity
- Rain
- Soil
- Water
- Air
Ans : Air
6. Filtration method is effective in separating ________ mixture
- solid-solid
- solid-liquid
- liquid-liquid
- liquid-gas
Ans : solid-liquid
7. Among the following _________is not a mixture
- Coffee with milk
- lemon juice
- water
- ice cream embedded with nuts.
Ans : water
II . Find whether the following statements are true or false. – if false give the correct answer
1. Air is not compressible.
Ans : False
Cu. An : Air is compressible
2. Liquids have no fixed volume but have fixed shape.
Ans : False
Cu. An : Liquids have fixed volume.
3. Particles in solids are free to move.
Ans : False
Cu. An : Particles in solids cannot move freely
4. When pulses are washed with water before cooking, the water is separated from them by the process of filtration .
Ans : True
5. Strainer is a kind of sieve which is used to separate a liquid from solid.
Ans : True
6. Grain and husk can be separated by winnowing.
Ans : True
7. Air is a pure substance
Ans : False
Cu. An : Air is mixture.
8. Butter from curds is separated by sedimentation
Ans : False
Cu. An : Butter from curds is separated by Churning
III. Fill up the blanks.
1. Matter is made up of _________
Ans : atoms
2. In solids, the space between the particles is less than in _________.
Ans : liquid and gas
3. Grains can be separated from their stalks by _________
Ans : Threshing
4. Chillies are removed from ‘upma’ by _________ method.
Ans : hand picking
5. The method employed to separate clay particles from water is _________
Ans : Filtration
6. Water obtained from tube wells is usually _________ water .
Ans : pure
7. Which among the following _________ will get attracted to by magnet? (safety pins, pencil and rubber band)
Ans : safety pin
8. Among the following items: safety pins, pencil and rubber band, _________ will get attracted to a magnet.
Ans : safety pin
IV. Complete the given analogy.
1. Solid : Rigidity :: Gas : _________
Ans : non – rigidity
2. Large Inter-particle space : Gas :: _________: Solid
Ans : very small Inter – parcticles Space
3. Solid : Definite shape : : ________ : Shape of the vessel.
Ans : liquid
4. Husk-grains : winnowing :: Sawdust- Chalk piece: ________
Ans : sieving
5. Murukku from hot oil: _________ : coffee powder residue from decoction
Ans : Filtration
6. Iron – Sulphur mixture : ____________: Mustard seeds from Urad-dhal: Rolling
Ans : Magnetic separation
V. a) Match the following
1. Breaks easily ( brittle) | Metal pan |
2. Bends readily | Rubber band |
3. Can be stretched easily | Cotton wool |
4. Gets compressed easily | Mud pot |
5. Gets heated readily | Plastic wire |
Ans : 1 – D, 2 – E, 3 – B, 4 – C, 5 – A |
B) Match the following
i) Separation of visible undesirable components | water mixed with chalk powder | Magnetic Separation |
ii) Separating of heavier and lighter components | sand and water | Decantation |
iii) Separation of insoluble impurities | iron impurities | Filtration |
iv) Separation of magnetic component from non- magnetic components | rice and stone | Hand-picking |
v) Separation of solids from liquids | husk and paddy | Winnowing |
Ans : 1 – D – D, 2 – E – E, 3 – A – C, 4 – C – A, 5 – B – B |
VI. Give very Short answer.
1. Define the term matter.
Matter occupies space and has mass.
2. How can husk or fine dust particles be separated from rice before cooking?
Husk or fine dust particles can be separated from rice before cooking by decantation process.
Procedure :
- Add water to the rice.
- Then husk or fine dust particles will be floated in water.
- Heavy rice settles to the bottom of the liquid is called sediment.
- The process of separating liquid above the sediment is called decantation.
3. Why do we separate mixtures?
- To remove harmful components.
- To extract component from other component.
- To obtain a component in a highly pure form.
4. Give an example for mixture and justify your answer with reason.
An example for mixture :
Milk
Reason :
Milk is a mixture because it contains water, fat, protein, etc.
5. Define Sedimentation.
The settling down of heavier components of a mixture when allowed to remain undisturbed for some time is called sedimentation.
6. Give the main difference between a pure substance and an impure substance.
Pure substance | Impure substance |
1. Pure substance is made up only one kind of particles. | Impure substance is made up of more than one kind of particles. |
(ex): Elements or Compounds | (ex): Mixture |
VII. Answer briefly
1. A rubber ball changes its shape on pressing. Can it be called a solid?
- Due to elastic force rubber ball changes its shape on pressing.
- Rubber ball has fixed shape and volume. So it can be called a solid.
2. Why do gases not have fixed shape?
- The particles in the gases are arranged far apart. They move freely.
- So gases do not have fixed shape.
- Ex : Air
3. What method will you employ to separate cheese (paneer) from milk? Explain.
- Centrifugation method will be used to separate cheese from milk.
- In this method the milk is taken in container and placed in a centrifuge machine and rotated rapidly.
- As the mixture rotates round rapidly, a force acts on the heavier suspended particles in it and bring them down to the bottom of the container, the lighter component remains on top.
4. Look at the picture given below and explain the method of separation illustrated.
- In the given picture sieving is used to separate bran from flour.
- Sieving is used when we have to separate solid particles of different sizes.
- (ex) : bran from flour.
5. How can you separate a mixture of a large quantity of tiny bits of paper mixed with pulses / dal?
- Mixture of a large quantity of tiny bits of paper mixed with pulse can be separated by winnowing.
- Winnowing is done by dropping the mixture slowly from a height in the presence of wind.
- Lighter solids (i.e) paper will be carried by wind and will be collected in a separate heap while heavier solids (i.e) pulses will fall closer and form a separate heap.
6. What is meant by food adulteration?
Sometimes, things that we buy in the market are mixed with harmful and unwanted substances. This process is called adulteration.
7. Mr. Raghu returns home on a hot summer day and wants to have buttermilk. Mrs. Raghu has only curds. What can she do to get buttermilk? Explain
Mrs. Raghu separates buttermilk from curds by the method of churning.
Explanation :
- The mixture is churned vigorously when solid butter will be collected on the sides of the vessel.
- Then she can get buttermilk separately.
VIII. Higher Order Thinking Skills.
1. Distinguish between properties of Solid, liquid, gas. Draw suitable diagram
Solids | Liquids | Gases |
1. Definite shape and volume | No definite shape, liquids attain the shape of the vessel in which they are kept. | Gases have neither a definite shape nor a definite volume. |
2. Incompressible | Compressible to a small extent. | Highly compressible |
3. There is little space between the particles of solid | These particles have a greater space between them. | The space between gas particles is the greatest. |
4. These particles attract the each other very strongly | The force of attraction between liquid particles is less than solid particles. | The force of attraction is least between gaseous particles. |
5. Particles of solid cannot move freely. | These particles move freely | Gaseous particles are in a continuous, random motion. |
2. Using suitable apparatus from your laboratory separate the mixture of chalk powder, mustard oil, water and coins. Draw a flow chart to show the separation process.
1. By the process of hand picking coins can be separate. | |
2. By the method of decantation chalk powder can be separated. | |
3. Water mixed with mustard oil is a heterogeneous mixture. It can be separated by separating funnel. |