CHAPTER 3
Practice Set 5
Let’s Separate the Components
Grade 6 Science • Maharashtra State Board • 30 Marks
Q.1 (A) Choose the correct option.
4 Marks
(1) Which mixture is mentioned as suitable for filtration using filter paper?
(2) What carries the lighter trash away during winnowing?
(3) Which state of water leaves the saucer during evaporation?
(4) By 2015, Dr. Uddhab Bharali had created more than __________ useful machines and tools.
Q.1 (B) Answer in one word or one term.
4 Marks
(1) The solid material that remains on a filter:
(2) The liquid that passes through the filter:
(3) The light waste separated from grains by wind:
(4) The insoluble solid that settles from muddy water:
Q.2 Study the assertion and reason. Choose the correct relation.
3 Marks
Assertion: Butter can be collected from the surface of buttermilk.
Reason: Butter is fatty and light.
Assertion: A sieve can separate two solid substances having particles of the same size.
Reason: Sieving uses a difference in particle size.
Assertion: Iron can be separated from non-magnetic waste with a magnet.
Reason: Iron is attracted towards a magnet.
Q.3 Classify the following.
4 Marks
(1) Magnetic substances
Iron, salt, cobalt, bran, nickel
(2) Methods involving a liquid and an insoluble solid
Filtration, winnowing, sedimentation, handpicking
(3) Methods mainly used for solid–solid mixtures
Sieving, evaporation, handpicking, winnowing
(4) States of the separated components during filtration
Solid, liquid, gas
Q.4 Observe the activity and answer.
4 Marks
A mixture of oil and water is poured into a transparent container. It is kept still until two layers appear.
(1) Which liquid forms the upper layer, and which forms the lower layer?
(2) Why must the bottom hole be closed at the correct moment while separating the liquids?
Muddy water is passed through an ordinary cloth or tea strainer.
(3) Will this always produce completely clean water?
(4) Which laboratory material can filter much finer particles?
Q.5 Complete the cause-and-effect table.
4 Marks
| Cause or Action | Effect or Result |
|---|---|
| Grain-and-chaff mixture is dropped from a height. | ____________________________ |
| Curd is churned for some time. | ____________________________ |
| Salt solution is kept under the Sun. | ____________________________ |
| A magnet is moved through waste containing iron. | ____________________________ |
Q.6 Answer the following.
5 Marks
(1) Why is repeatedly pouring the upper oil layer not sufficient to separate all the oil and water accurately?
(2) How can a transparent container with a hole at the bottom separate oil and water more effectively?
(3) State two differences between sieving and filtration.
Q.7 Answer the questions about scientific work and inventions.
3 Marks
(1) For which three main fields did Dr. Uddhab Bharali create useful machines and tools?
(2) Which international organisation honoured him in the “Technology of the Future” competition?
(3) What special centre did Dr. Bharali establish?
Q.8 Give scientific reasons.
3 Marks
(1) A transparent container is useful while separating oil and water.
(2) Filter paper can separate finer particles than an ordinary strainer.
(3) Pure salt is not obtained immediately after the evaporation of seawater.
CHAPTER 3
Practice Set 5 – Solutions
Let’s Separate the Components
Q.1 (A) Choose the correct option.
(1) Mixture suitable for filtration using filter paper
Answer: (b) Muddy water
(2) Substance that carries away lighter trash
Answer: (c) Wind
(3) State of water leaving during evaporation
Answer: (b) Gaseous
(4) Machines and tools created by Dr. Bharali
Answer: (c) More than 160
Q.1 (B) Answer in one word or one term.
(1) Solid material remaining on a filter
Answer: Insoluble solid
(2) Liquid passing through a filter
Answer: Filtered liquid
(3) Light waste separated from grains
Answer: Chaff
(4) Solid settling from muddy water
Answer: Soil
Q.2 Assertion and Reason.
(1) Butter can be collected from the surface because it is fatty and light.
Answer: Both statements are true, and the reason explains the assertion.
Option (a)
(2) A sieve can separate solids of the same particle size because sieving uses a difference in particle size.
Answer: The assertion is false, but the reason is true.
Option (d)
(3) Iron can be separated with a magnet because iron is attracted towards it.
Answer: Both statements are true, and the reason explains the assertion.
Option (a)
Q.3 Classify the following.
(1) Magnetic substances
Answer: Iron, cobalt and nickel
(2) Methods involving a liquid and an insoluble solid
Answer: Filtration and sedimentation
(3) Methods mainly used for solid–solid mixtures
Answer: Sieving, handpicking and winnowing
(4) States of the components separated during filtration
Answer: Solid and liquid
Q.4 Observe the activity and answer.
(1) Which liquids form the upper and lower layers?
Answer: Oil forms the upper layer, and water forms the lower layer.
(2) Why must the bottom hole be closed at the correct moment?
Answer: The hole must be closed immediately after the lower water layer flows out. Otherwise, the oil will also flow into the lower container.
(3) Will cloth or a tea strainer always produce completely clean water?
Answer: No. Very fine soil particles may pass through the holes of an ordinary cloth or tea strainer.
(4) Which laboratory material can filter much finer particles?
Answer: Filter paper
Q.5 Complete the cause-and-effect table.
| Cause or Action | Effect or Result |
|---|---|
| Grain-and-chaff mixture is dropped from a height. | Heavy grains fall straight down, while lighter chaff is carried away by wind. |
| Curd is churned for some time. | Butter particles stick together, form a lump and float on the buttermilk. |
| Salt solution is kept under the Sun. | Water changes into vapour, and solid salt remains behind. |
| A magnet is moved through waste containing iron. | Iron is attracted towards the magnet and separates from the non-magnetic waste. |
Q.6 Answer the following.
(1) Why is repeatedly pouring the upper oil layer insufficient?
Answer: While pouring, some oil may remain with the water or some water may flow with the oil. Therefore, all the oil and water cannot be separated accurately by repeatedly pouring the upper layer.
(2) How does a container with a bottom hole separate oil and water?
Answer: Keep the bottom hole closed and pour the mixture into the transparent container. After two layers form, open the hole. Water from the lower layer flows out first. Close the hole as soon as the water has flowed out and the oil reaches it. Water collects below, while oil remains in the upper container.
(3) State two differences between sieving and filtration.
Sieving
It is mainly used for a mixture of two solid substances whose particles differ in size.
Filtration
It is used for a mixture containing a liquid and an insoluble solid.
Sieving
A suitable sieve or mesh separates smaller solid particles from larger ones.
Filtration
A strainer, fine sieve or filter paper holds back the solid while the liquid passes through.
Q.7 Scientific work and inventions.
(1) For which fields did Dr. Bharali create useful machines and tools?
Answer: Agriculture, industry and persons with disabilities.
(2) Which international organisation honoured him?
Answer: NASA
(3) What special centre did he establish?
Answer: He established a special centre for the research and creation of various machines.
Q.8 Give scientific reasons.
(1) A transparent container is useful while separating oil and water.
Answer: It allows us to see the two separate liquid layers and close the bottom hole at the correct moment when the lower water layer has flowed out.
(2) Filter paper separates finer particles than an ordinary strainer.
Answer: Filter paper is a mesh of extremely microscopic pores. These pores hold back much finer insoluble particles.
(3) Pure salt is not obtained immediately after seawater evaporates.
Answer: The raw salt left in salt pans contains stones, dirt and other impurities. Various other separation methods are required to obtain pure salt.