Category: Class 6

Students can download 6th Science Term 3 Chapter 3 Chemistry in Everyday Life Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 3 Chapter 3 Chemistry in Everyday Life

Samacheer Kalvi 6th Science Chemistry in Everyday Life Text Book Back Questions and Answers

I. Choose the correct Answer:

Question 1.
Soaps were originally made from ………
a. proteins
b. animal fats and vegetable oils
c. chemicals extracted from the soil
d. foam booster
Answer:
b. animal fats and vegetable oils.

Question 2.
The saponification of a fat or oil is done using _______ solution for hot process.
(a) Potassium hydroxide
(b) Sodium hydroxide
(c) Hydrochloric acid
(d) Sodium chloride
Answer:
(b) Sodium hydroxide

Question 3.
Gypsum is added to the cement for ………..
a. fast setting
b. delayed setting
c. hardening
d. making paste
Answer:
b. delayed setting

Question 4.
Phenol is ……..
a. carbolic acid
b. acetic acid
c. benzoic acid
d. hydrochloric acid
Answer:
a. carbolic acid

Question 5.
Natural adhesives are made from ………..
a. Protein
b. fat
c. starch
d. vitamins
Answer:
c. starch

II. Fill in the Blanks

1. ………… gas causes tears in our eyes while cutting onions.
2. Water, coconut oil and ……….. are necessary for soap preparation.
3. ………..is called a farmer’s best friend.
4. …………. fertilizer is ecofriendly.
5. ………… is an example for natural adhesive.

Answer:

1. Propane Thiol Oxide
2. NaOH
3. Earthworm
4. Artificial
5. Starch

III. True or False. If False, give the correct statement.

1. Concentrated phenol is used as a disinfectant.
2. Gypsum is largely used in medical industries.
3. Plaster of Paris is obtained from heating gypsum.
4. Adhesives are the substances used to separate the components.
5. NPK are the primary nutrients for plants.

Answer:

1. False. – Low concentrated Phenol is used as a disinfectant.
2. False – Epsum is largely used in medical industry.
3. True.
4. False – Adhesives are substances that are used to join two (or) more components.
5. True

IV. Match the following:

Answer
1. – c
2. – d
3. – e
4. – b
5. – a

V. Arrange the following statements in the correct sequence:

1. Pour that solution into an empty matchbox, soap can be obtained after drying.
2. Take the necessary quantity of water in a jar.
3. Then add coconut oil drop by drop and stir it well.
4. Add concentrated sodium hydroxide in the jar and allow it to cool.
5. Try this soap to wash your handkerchief.
6. Cover your work area with old newspaper.

Answer:

1. Cover your work area with old newspaper.
2. Take the necessary quantity of water in a jar.
3. Add concentrated sodium hydroxide in the jar and allow it to cool.
4. Then add coconut oil drop by drop and stir it well.
5. Pour that solution into an empty matchbox, soap can be obtained after drying.
6. Try this soap to wash your handkerchief.

VI. Analogy:

1. Urea : Inorganic fertilizer :: Vermi Compost: …………
2. ……….. : Natural Adhesives :: Cello tape : Artificial Adhesives

Answer:

1. Natural Fertilizer
2. Starch

VII. Give Very Short Answer:

Question 1.
What are the three main constituents of soap?
Answer:
The three main constituents of soap are Lye (Sodium hydroxide), coconut oil, and water.

Question 2.
What are the two different types of molecules found in the soap?
Answer:
The two types of molecules found in the soap are

1. water-loving
2. water-hating.

Question 3.
Give an example of inorganic fertilizer.
Answer:
The Inorganic fertilizers are Urea, Ammonium sulphate, and Superphosphate.

Question 4.
Mention any three physical properties of phenol.
Answer:
Phenol properties:

1. It is a weak acid.
2. It is a volatile, white crystalline powder.
3. It is a colourless solution but changes into the red in the presence of dust.

Question 5.
Explain the uses of plaster of Paris.
Answer:
Uses of plaster of pairs:

1. In making blackboard chalks.
2. In surgery for setting fractured bones.
3. For making casts for statues and toys etc.
4. In the construction industry.

Question 6.
What are the ingredients of the cement?
Answer:
The ingredients of the cement are lime, clay, and gypsum.

Question 7.
Why gypsum is used in cement production?
Answer:
Gypsum is added to control the setting of cement.

VIII. Give Short Answer:

Question 1.
Why earthworm is called a farmer’s friend?
Answer:

1. Earthworms take organic wastes as food and produce compost castings.
2. They provide a multitude of services to improve soil health and consequently plant health.
3. So earthworm is called a farmer’s friend.

Question 2.
Explain the process of manufacturing cement.
Answer:
The cement is manufactured by crushing naturally occurring minerals such as limestone, clay, and gypsum through a milling process.

Question 3.
What are the uses of Gypsum?
Answer:

1. Used as fertilizers
2. Used in the process of making cement and plaster of Paris.

IX. Answer in detail

Question 1.
How are detergents manufactured?
Answer:
Manufacture of Detergents:
Materials used:
Acid slurry, Soda ash (or) Sodium Carbonate, Trisodium phosphate (TSP), sodium tripolyphosphate (STPP), Carboxy Methyl Chloride (or) Cellulose, Glauber’s salt, colour perfume and brightner.

Preparation:

1. Acid slurry is first neutralised.
2. Then neutralised Acid Slurry is mixed with Soda ash and kept for one hour for completion of reaction.
3. Other ingredients such as Trisodium phosphate (TSP), Sodium tripolyphosphate (STPP), Carboxy Methyl Chloride (or) Cellulose, Glauber’s salt, colour, perfume, brightner are then blended to the neutralised Acid Slurry with continuous mixing.
4. Then the mixture is dried.
5. Now we get detergent powder.

X. Questions based on Higher Order Thinking Skills

Question 1.
Ravi is a farmer; he rears many cattle in his farm. His field has many biowastes. Advise Ravi on how to change this biowaste to compost by using vermicomposting techniques. Explain the benefits of vermi castings?
Answer:

1. Make a pit of 30 cm or take a wooden box.
2. Place a thin net on the base of the pit or wooden box.
3. Fill it with sand for about 1-2 cm.
4. Spread some plant wastes (like a dry leaf, flower) and biodegradable wastes on it.
5. Sprinkle some water.
6. Add some earthworms to these substances and cover them with an old cloth or dried coconut leaf.
7. We can find that vermicompost is formed after four weeks.
8. Use this vermicompost as manure for plants and conserve soil fertility.

Advantages of using vermicompost:

1. Vermicompost is an excellent organic manure for sustainable agro-practices.
2. Vermicompost is rich in essential plant nutrients.
3. In improves soil structure texture, aeration, and water holding capacity and prevents soil erosion.
4. Vermicompost is rich in nutrients and an eco-friendly amendment to the soil for farming and terrace gardening.
5. It enhances seed germination and ensures good plant growth.
6. Vermicompost can be prepared easily.

Samacheer Kalvi 6th Science Chemistry in Everyday Life Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
………. to remove strong strains on the clothes.
(a) Detergents soap
(b) Bathing soap
(c) Bleaching powder
(d) None of these.
Answer:
(c) Bleaching powder

Question 2.
_______ are the substances which can undergo chemical changes to produce certain materials.
(a) Soaps
(b) Fertilizers
(c) Plastics
(d) All the above
Answer:
(d) All the above

Question 3.
If 50 kg of Superphosphate is added to the soil, how much phosphorus would the soil get?
(a) 4 – 4.5 kg
(b) 8 – 9 kg
(c) 12 – 13 kg
(d) 16 – 18 kg
Answer:
(a) 4 – 4.5 kg

Question 4.
All the plants get their _______ from the soil.
(a) Nutrients
(b) Water
(c) Nitrogen
(d) All the above
Answer:
(a) Nutrients

Question 5.
The molecular formula of Epsom is _______
(a) CaSO₄1/2H₂O
(b) C₆H₅OH
(c) MgSO₄.7H₂O
(d) CaSO₄.2H₂O
Answer:
(c) MgSO₄.7H₂O

II. Fill in the blanks:

1. ……… is a natural indicator.
2. ……….. molecules goes and joins with dirt and oil in the cloth.
3. Fertilizer facilitates the growth of ………….
4. ………….. is used to fix bone fractures.
5. Epsom salt is ………….

Answer:

1. turmeric powder
2. Water hating molecules
3. plants
4. Plaster of Paris
5. Magnesium Sulphate Hydrate

III. Match the Following:

Answer:
1. – b
2. – a
3. – d
4. – c

IV. Arrange the following statements in correct sequence:

1. One side water-loving and other water-hating molecules.
2. When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
3. The dirt surrounded by the detergent molecules floats in the water making it dirty.
4. Finally, the cloth is clean.
5. The detergent molecules have two sides.
6. Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.

Answer:

1. The detergent molecules have two sides.
2. One side water-loving and other water-hating molecules.
3. Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
4. When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
5. The dirt surrounded by the detergent molecules floats in the water making it dirty.
6. Finally, the cloth is clean.

V. Analogy:

1. Black board chalks : ………….. : : Plant growth : Epsum
2. …………. : Calcium Sulphate Dihydrate : : Plaster of Paris : Calcium Sulphate Hemihvdrate
3. ………. : Mortar : : Construction of bridges : Concrete

Answer:

1. Plaster of Paris
2. Gypsum
3. Construction of house walls.

VI. Give Very Short Answer

Question 1.
What are the principal nutrients?
Answer:
Principal nutrients are NPK

1. Nitrogen (N)
2. Phosphorus (P)
3. Potassium (K)

Question 2.
What are fertilizers?
Answer:
Fertilizers are organic (or) inorganic materials that we add to the soil to provide one (or) more nutrients to the soil.

Question 3.
Give two examples of organic fertilizers?
Answer:

1. Compost
2. Vermicompost

Question 4.
Why is called inorganic fertilizers?
Answer:
The fertilizers prepared by using natural elements by making them undergo chemical changes in the laboratories are called inorganic fertilizers.

Question 5.
Why is called Portland cement?
Answer:
It was named “Portland” cement because it resembled the high-quality building stones found in Portland, England.

VII. Answer in details:

Question 1.
What is Epsum? Mention it’s used.
Answer:
Epsum:

1. Epsum salt is magnesium Sulphate Hydrate.
2. Its molecular formula – MgSO₄. 7H₂O

Uses:

1. Eases stress and relaxes the body.
2. Helps muscles and nerves to function properly.
3. Medicine for skin problems.
4. Improving plant growth in agriculture.

Question 2.
Write about the Phenol and its uses.
Answer:
Phenol:

1. Phenol is a Carbolic acid of an organic compound.
2. It’s molecular formula C₆H₅OH
3. It is a weak acid.
4. It is a volatile, white crystalline powder.
5. It is a colourless solution but changes into the red in the presence of dust.
6. It irritates when exposed to human skin.

Uses:

1. It’s used industrial.
2. Low concentration of Phenol is used in mouth wash, disinfectant in household cleaners.
3. It is used as a surgical antiseptic since it kills microorganisms.

Question 3.
Tabulate the nutrients present in inorganic fertilizers.
Answer:

Students can download 6th Science Term 3 Chapter 2 Water Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 3 Chapter 2 Water

Samacheer Kalvi 6th Science Water Text Book Back Questions and Answers

I. Choose the correct Answer:

Question 1.
Around 97% of water available on earth is water.
a. fresh
b. pure
c. salty
d. polluted
Answer:
c. salty

Question 2.
Which of the following is not a part of the water cycle?
(a) evaporation
(b) condensation
(c) rain
(d) distillation
Answer:
(d) distillation

Question 3.
Which of the following processes add water vapour to the atmosphere?
i. Transpiration
ii. Precipitation
iii. Condensation
iv. Evaporation
a. ii and iii
b. ii and iv
c. i and iv
d. i and ii
Answer:
c. i and iv

Question 4.
About 30% of the freshwater is found in?
(a) glaciers
(b) groundwater
(c) other sources of water
(d) 0.3%
Answer:
(b) groundwater

Question 5.
Using R.O. plant at home eliminates lot of non-potable water. The best way to effectively use the expelled water of R.O. plant is ……….
a. make the expelled water go and seep near the bore well
b. use it for watering plants
c. to drink the expelled water after boiling and cooling
d. to use for cooking as the water is full of many nutrients
Answer:
b. use it for watering plants

II. Fill in the Blanks

1. Only ……… percent of natural water is available for human consumption.
2. The process of changing water into its vapour is called ………..
3. ……….. is built on rivers to regulate water flow and distribute water.
4. Water levels in rivers increase greatly during …………
5. Water cycle is also called as ………..

Answer:

1. 3%
2. Evaporation
3. Dam
4. Rainy days
5. hydrological cycle

III. True or False. If False, give the correct statement.

1. Water present in rivers, lakes and ponds is unfit for use by human beings.
2. Seas are formed when the water table meets the land surface.
3. The evaporation of water takes place only in sunlight.
4. Condensation results in the formation of dew on grass.
5. Seawater can be used for irrigation as such.

Answer:

1. False – Water present in rivers, lakes and ponds is fit for use by human beings.
2. True
3. False – The evaporation of water takes place in any source of heat.
4. True
5. False – Sea water can not be used for irrigation as such.

IV. Match the following

Answer:
1. – e
2. – a
3. – b
4. – c
5. – d

V. Arrange the following statements in the correct sequence

1. These vapours condense to form tiny droplets of water.
2. The water droplets come together to form large water droplets.
3. The heat of the sun causes evaporation of water from the surface of the earth, oceans, lakes, rivers and other water bodies.
4. The large water droplets become heavy and the air cannot hold them, therefore, they fall as rains.
5. Water vapour is also continuously added to the atmosphere through transpiration from the surface of the leaves of trees.
6. Warm air carrying clouds rises up.
7. Higher up in the atmosphere, the air is cool.
8. These droplets floating in the air along with the dust particles form clouds.

Answer:

1. The heat of the sun causes evaporation of water from the surface of the earth, oceans, lakes, rivers and other water bodies.
2. Water vapour is also continuously added to the atmosphere through transpiration from the surface of the leaves of trees.
3. These droplets floating in the air along with the dust particles form clouds.
4. Warm air carrying clouds rises up.
5. Higher up in the atmosphere, the air is cool.
6. These vapours condense to form tiny droplets of water.
7. The water droplets come together to form large water droplets.
8. The large water droplets become heavy and the air cannot hold them, therefore, they fall as rains.

VI. Analogy:

Question 1.
Population explosion : Water scarcity : : Recycle : ………..
Answer:
Water management

Question 2.
Groundwater : ……….. : : Surface-water : Lakes
Answer:
Wells

VII. Give Very Short Answer

Question 1.
Name four different sources of water.
Answer:
Rivers, wells, lakes, glaciers, ponds, etc.

Question 2.
How do people in cities and rural areas get water for various purposes?
Answer:
People get water from wells, canals, tanks, ponds, rivers, water tanks, hand pipes for various purposes.

Question 3.
Take out of cooled bottle of water from refrigerator and keep it on a table. After some time you notice a puddle of water around it. Why?
Answer:
The cooled surface of the bottle cools the air around it and the water vapour of the air condenses. So after some time, a puddle of water can be noticed around the bottle.

Question 4.
We could see clouds almost every day. Why doesn’t it rain daily?
Answer:
When the air around the clouds is cool the clouds then only rain comes. That is the reason why we can’t get rain daily.

Question 5.
Name the places where water is found as ice.
Answer:
Polar ice-caps, Ice sheets, and glaciers in Artie region arid Antarctica.

Question 6.
How do aquatic animals manage to live in Arctic and Antarctic Circle?
Answer:
Floating layer of ice acts as a protective coat and does not permit heat to escape from water. So aquatic animals manage to live in Arctic and Antarctic circle.

Question 7.
What are the types of rainwater harvesting?
Answer:
There are two types of rainwater harvesting.

1. Collecting water from where it falls.
2. Collecting rainwater by constructing bunds.

VIII. Give Short Answer

Question 1.
Differentiate between surface water and groundwater.
Answer:

Question 2.
Write a few slogans of your own on the topic “Save Water”.
Answer:

1. “To a thirsty man, a drop of water is worth more than a sack of gold”.
2. “Water covers 2/3 of the surface of the earth. But only 0.002% is drinkable. Save water”
3. “Save water to secure your future”
4. “Don’t make nature cry, keep your water clean”
5. “Store water for dry days”.

Question 3.
About 71% of earth’s surface is covered with water, then why do we face scarcity of water?
Answer:
71% of the earth’s surface is covered with water. The freshwater will be only 3%. It remains the same. But the water useful for plants, animals, and men is increasing day by day. So we face water scarcity.

Question 4.
Give reason for the following statement – Sewage should not be disposed of in rivers or oceans before treatment.
Answer:
Sewage contains harmful and toxic chemicals. They can disturb the ecosystem of the living animals, in the rivers or oceans. So it should be treated effectually before disposing into rivers or oceans.

Question 5.
The freshwater available on earth is only 3%. We cannot increase the amount of water. In that case, how can sustain the water level?
Answer:

1. The sewage water treatment is to be adopted.
2. Decrease the usage of pesticides, insecticides, and fertilizers in agriculture.
3. Protect forest and trees.
4. Adopt drip irrigation and sprinkler irrigation in agriculture.
5. Rainwater harvesting should be implemented in every building.
6. Create awareness about the impact of throwing wastes into the water bodies.

IX. Answer in detail

Question 1.
What is potable water? List down its characteristics.
Answer:
The water which is fit for drinking by human beings is called potable water, characteristics

1. It is transparent.
2. It is odourless and colourless.
3. It is harmless or free from disease-causing bacteria.

Question 2.
Who is known as waterman of India? Browse the net and find the details about the award, the waterman received for water management. State the findings by drafting a report.
Answer:
The ‘Waterman of India’ is Dr. Rajendra Singh. He is a well-known water conservationist and environmentalist from Alwar district, Rajasthan.

Awards:

1. He gets the Ramon Magsaysay award for community leadership in 2001.
2. In 2005, he got the Jamnalal Bajaj Award for Science and Technology for rural development.
3. In 2008, The Guardian named him amongst its list of 50 people who could save the planet.
4. In 2015, he won the Stockholm Water Prize. He runs an NGO called ‘Tarun Bharat Sangh’ (TBS), which was founded in 1975.
5. In 2016, he was bestowed with Ahimsa Award by the Institute of Jainology based in UK.

Question 3.
What is rainwater harvesting? Explain in a few sentences how it can be used in houses.
Answer:
Rainwater harvesting:
Direct collection and use of rainwater are called rainwater harvesting.

There are two types of rainwater harvesting.

(a) Collecting water from where it falls.
Example: Collecting water from the rooftops of the houses or buildings (Roof water harvesting).

(b) Collecting flowing rainwater.
Example: Collecting rainwater by constructing ponds with bund.

X. Questions Based on Higher Order Thinking Skills.

Question 1.
When there is no pond or lake in an area, will there be the formation of clouds possible in that area?
Answer:
When there is no pond or lake in an area formation of clouds will be possible. Transpiration from the aerial parts of all plants and trees will evaporate water and it will form clouds.

Question 2.
To clean the spectacles, people often breathe out on glasses to make them wet. Explain why do the glasses become wet.
Answer:
When we breathe out, the hot air comes out from our mouth which gets condensed and changed into tiny water droplets, and glasses become wet.

XI. Crossword

Down:
1. A method of water conservation.
2. Process of getting water vapour from seawater.
6. Water stored in dams is used for the generation of ………..

Across:
3. ………. is a large body of non -potable water found in nature.
4. In summer, the body loses water as ……..
5. Plants undergo ………….. and contribute to the water cycle.

Answer:

XII. Observe the given graph carefully and answer the questions.

Question 1.

1. What percentage of water is seen in fish?
2. Name the food item that has the maximum amount of water in its content.
3. Name the food item that has a minimum amount of water in its content.
4. The human body consists of about ………. percentage of water.
5. Specify the food item that can be consumed by a person when he / she is suffering from dehydration.

Answer:

1. Fish – 70%
2. Watermelon
3. Fish
4. 60%
5. watermelon, pineapple

Question 2.
Look at the map of Tamilnadu showing annual rainfall and answer the questions given below

a. Identify the districts that get only low annual rainfall in Tamilnadu.
Answer:
northwest zone (Coimbatore, Erode, Namakkal, Karur)

b. Identify the districts that get a medium annual rainfall in Tamilnadu.
Answer:
Pudhukottai, Virthunagar, Sivagangai, Salem, Dindigul, Theni, Vellore.

c. State the districts that enjoy high annual rainfall in Tamilnadu.
Answer:
Tirunelveli, Kanyakumari, Chennai, Vizhupuram, Thiruvallur, Kadalur, Nagapattinam

Samacheer Kalvi 6th Science Water Additional Important Questions and Answers

I. Choose the best Answer:

Question 1.
If the total water on earth be 100% the percentage of freshwater is ………..
(a) 97%
(b) 93%
(c) 3%
(d) 0.3%
Answer:
(c) 3%

Question 2.
_______ is a transparent, tasteless, odourless, chemical substance.
(a) Petrol
(b) Wax
(c) Water
(d) Kerosene
Ans:
(c) Water

Question 3.
Which one is not an example of groundwater?
(a) hand pump
(b) borewell
(c) wetland water
(d) well
Answer:
(c) wetland water

Question 4.
Water from oceans, lakes, ponds, and rivers evaporates due to the heat of _______
(a) Sun
(b) Pressure
(c) Atmosphere
(d) None of these
Answer:
(a) Sun

Question 5.
………. are wetlands where water bodies meet the sea.
(a) lake
(b) well
(c) estuary
(d) glacier
Answer:
(c) estuary

II. True or False.

1. Maximum surface water is stored in lakes.
2. The oceanic volcanoes add salts to the sea.
3. Water is a non-transparent chemical.
4. Transpiration takes place in rivers and lakes.
5. Nitrogen is used for the treatment of drinking water.

Answer:

1. True
2. True
3. False
4. False
5. False

III. Match the Following:

Answer:
1. – v.
2. – iv.
3. – i.
4. – ii.
5. – iii.

IV. Analogy:

1. Low rainfall: Water scarcity : : Recycling Water : ………..
2. Frozen Water : Glaciers : : Surface Water : ………..
3. Evaporation : Sea : : …………. : Trees
4. Filtering : Sand : : ………….. : Ammonia
5. Solid State : ………… : : Gaseous State : Vapour

Answer:

1. Water Management
2. River
3. Transpiration
4. Disinfection
5. Ice

V. Very Short Answer

Question 1.
What is the composition of water?
Answer:

1. Water is composed of two atoms of hydrogen combining with one atom of oxygen gas.
2. The molecular formula of water is H₂O.

Question 2.
What is water?
Answer:
Water is a transparent, tasteless, odourless and nearly colourless chemical substance.

Question 3.
What is saltwater?
Answer:
Water which has more than 3% salt is called saltwater. We can not drink and use this water.

Question 4.
What are the three stages in the water cycle?
Answer:
Evaporation, condensation and precipitation.

Question 5.
What is transpiration?
Answer:
It is the process of loss of water from the aerial parts of a plant in vapour form is called transpiration.

VI. Long Answer Questions:

Question 1.
Explain the three stages of the water cycle.
Answer:

1. Water cycle is a continuous process.
2. It is also called the hydrological cycle.
3. The stages are

1. Evaporation :
Water from oceans, lakes, ponds and rivers evaporates due to the heat of the Sun.

2. Condensation:
Water vapour which enters into the atmosphere by evaporation moves upward with air, gets cooled and changes into tiny water droplets that form clouds in the sky.

3. Precipitation:
Millions of tiny droplets collide with each other to form large droplets. The air around the clouds is cool these drops of a waterfall in the form of snow or rain.

Question 2.
How water is conserved by water management method?
Answer:
Water management consists of the following factors:

1. Bringing awareness about the bad effects of throwing wastes into the water bodies.
2. Recycling of water by separating pollutants.
3. Minimizing the use of chemical fertilizers in agriculture. It reduces the pollution of underground water.
4. Controlling deforestation.
5. Adopting drip irrigation and sprinkler irrigation in agriculture. In this way, a lesser amount of water can be used for irrigation.

Students can download 6th Science Term 3 Chapter 1 Magnetism Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 3 Chapter 1 Magnetism

Samacheer Kalvi 6th Science Magnetism Text Book Back Questions and Answers

1. Choose the correct answer:

Question 1.
An object that is attracted by a magnet.
a. wooden piece
b. plain pins
c. eraser
d. a piece of paper
Answer:
b. Plain pins

Question 2.
People who made mariner’s compass for the first time.
(a) Indians
(b) Europeans
(c) Chinese
(d) Egyptians
Answer:
(c) Chinese

Question 3.
A freely suspended magnet always comes to rest in the direction
a. North-east
b. South-west
c. East-west
d. North-south
Answer:
d. North-South

Question 4.
Magnets lose their properties when they are
(a) used
(b) stored
(c) hit with a hammer
(d) cleaned
Answer:
(c) hit with a hammer

Question 5.
Mariner’s compass is used to find the
a. speed
b. displacement
c. direction
d. motion.
Answer:
c. direction

II. Fill in the Blanks

1. Artificial magnets are made in different shapes such as ……….., ………… and ………..
2. The Materials which are attracted towards the magnet are called ………..
3. Paper is not a ……….. material.
4. In olden days, sailors used to find direction by suspending a piece of ………..
5. A magnet always has ………. poles.

Answer:

1. Oval shape, Disc Shape, cylindrical shape
2. magnetic materials
3. magnetic
4. lodestone
5. Two

III. True or False. If False, give the correct answer.

1. A cylindrical magnet has only one pole.
2. Similar poles of a magnet repel each other.
3. Maximum iron filings stick in the middle of a bar magnet when it is brought near them.
4. A compass can be used to find East-West direction at any place.
5. Rubber is a magnetic material.

Answer:

1. False – A cylindrical magnet has two poles.
2. True
3. False – Maximum iron fillings stick in the poles of a bar magnet when it is brought near them.
4. False – A. compass can be used to find north-south direction at any place.
5. False – Rubber is a non-magnetic material.

IV. Match the following

Answer:
1. – d
2. – c
3. – b
4. – a

V. Circle the odd ones and give reasons

Question 1.
Iron, nail, pins, rubber tube, needle
Answer:
Iron, nail, pins,  needle
Rubber tube is a non-magnetic substance.

Question 2.
Lift, escalator, electromagnetic train, electric bulb
Answer:
Lift, escalator, electromagnetic train,
Electromagnet is not used in an electric bulb.

Question 3.
Attraction, repulsion, pointing direction, illumination
Answer:
Attraction, repulsion, pointing direction,
Illumination is not a magnetic property.

VI. The following diagrams show two magnets near one another. Use the words, ‘Attract, Repel,Turn around’ to describe what happens in each case:

Answer:
(a) Attract. Opposite poles S – N attracts each other.
(b) Repel. Like poles S – S repel each other.
(c) Attract. Opposite poles N – S attract each other.
(d) Turn around.
(e) Repel. Like poles N – N repel each other.
(f) Turn around.

VII. Write down the names of substances.

Answer:

VIII. Give Short Answer

Question 1.
Explain the attraction and repulsion between magnetic poles.
Answer:

1. Like poles (N – N, S – S) repel each other.
2. Unlike poles (N – S, S – N) attract each other.

Question 2.
A student who checked some magnets in the school laboratory found out that their magnetic force is worn out. Give three reasons for that?
Answer:
Magnets lose their properties if they are heated or dropped from a height or hit with a hammer.

IX. Answer in detail

Question 1.
You are provided with an iron needle. How will you magnetize it?
Answer:

1. Place the iron needle on the table.
2. Take a bar magnet and place one of its poles near one edge of the iron needle.
3. Rub from one end to another without changing the direction of the pole of the magnet.
4. Repeat the process 30 to 40 times. The needle will be magnetized.
5. If it will not attract pin or iron fillings continue the same process for some more time.

Question 2.
How does electromagnetic train work?
Answer:

1. Electromagnets are used in electromagnetic trains.
2. Electromagnets are magnetised when current flows through them. When the direction of the current is changed, poles will be changed.
3. Magnets are attached at the bottom of the train and rail tracks.
4. The train is lifted from track up to 10 cm height by the property of the same poles repel each other.
5. By using attraction and repulsion at the same time between the magnets in tracks and bottom of train move forward.
6. The magnets are controlled by electricity.
7. There is no friction. So the train can easily attain a speed of 300 km/ h.

X. Questions based on Higher Order Thinking Skills

Question 1.
You are provided with iron filings and a bar magnet without labelling the poles of the magnet. Using this ……….

a. How will you identify the poles of the magnet?
Answer:

1. When we place the bar magnet in iron fillings a large number of iron fillings stick on the two ends of the bar magnet. These ends are poles of the magnet.
2. Poles will attract more iron filings. Because poles have high magnetic strength.

b. Which part of the bar magnet attracts more iron filings? Why?
Answer:
The more iron filings are attracted by the poles of the magnet because the poles have more concentrated magnetic power.

Question 2.
Two bar magnets are given in figure A and B. By the property of attraction, identify the North pole and the South pole in the bar magnet (B)

Answer:
Opposite poles attract each other. The second pole of magnet A is N (north pole). So magnet B has S – N poles. Then only they will attract.

Question 3.
Take a glass of water with a few pins inside. How will you take out the pins without dipping your hands into the water?
Answer:

1. Take a bar magnet.
2. Tie it in a thread.
3. Dip the tied magnet into the glass of water.
4. The pins are attracted by the magnet.
5. Now take out the magnet from the glass of water.
6. Collect the pins from the magnet.

Samacheer Kalvi 6th Science Magnetism Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
Which is not attracted by a magnet?
(a) Iron
(b) Cobolt
(c) Nickel
(d) Rubber
Answer:
(d) Rubber

Question 2.
Among the following which one is a magnetic substance?
(a) Nickel
(b) Sodium
(c) Oxygen
(d) Potassium
Answer:
(a) Nickel

Question 3.
Who invented leading stone?
(a) Indians
(b) Europians
(c) Chinese
(d) Americans
Answer:
(c) Chinese

Question 4.
Magnets lose their properties if they are _______
(a) dipped in water
(b) dipped in oil
(c) heated
(d) in freezer
Answer:
(c) heated

Question 5.
The maximum speed of electromagnetic train is
(a) 380 km/hr
(b) 600 km/h
(c) 480 km/h
(d) 690 km/h
Answer:
(b) 600 km/h

II. Fill in the blanks:

1. Magnets are used to find directions. So they are called as ………..
2. ……….. is the ore with attracting property.
3. Ever silver spoon is a ……….. material.
4. ……….. is used to seperate iron from wastages.
5. The attractive force of magnet is high near …………

Answer:

1. leading stem
2. Magnetite
3. non-magnetic
4. electromagnet
5. Poles

III. Match the Following:

Answer:
1. – v.
2. – iii.
3. – i.
4. – ii.
5. – iv.

IV. Very Short Answer Questions:

Question 1.
What are artificial magnets?
Answer:
Man-made magnets are called artificial magnets.
(Eg.) bar-magnets, horseshoe magnets.

Question 2.
What are the different types of artificial magnets?
Answer:

1. Bar-magnet, Horseshoe magnet, Ring magnet and Needle magnet are generally used artificial magnets.
2. Oval-shape, Disc shape and cylindrical shape magnets are also available.

Question 3.
What are magnetic substances?
Answer:
Substances which are attracted by magnets are called magnetic substances. (Eg.) Iron, Cobolt, Nickel

Question 4.
What are non-magnetic substances?
Answer:
Substances which are not attracted by magnets are called non-magnetic substances. (Eg.) Paper, Plastic etc.

Question 5.
What are the uses of magnets?
Answer:

1. We use various equipment with magnets in day to day life.
2. We use magnets in speakers, small electric motors, some door locks, bags, some toys, compass, pencil boxes, phone covers, pin holders and magnetic crane.

V. Long Answer Questions:

Question 1.
What are the storage methods of magnets?
Answer:

1. Improper storage can also cause magnets to lose their properties.
2. To keep them safe, bar magnets should be kept in pairs with their unlike poles on the same side.
3. They must be seperated by a piece of wood and two pieces of soft iron should be placed across their ends.
4. For a horse shoe magnet a single piece of soft iron can be used as a magnetic keeper across the poles.

Question 2.
How to find directions with a magnet?
Answer:

1. Tie a piece of thread to the centre of a bar magnet and suspend it freely.
2. Note the direction in which the magnet stops.
3. Draw a line on a cardboard sheet along the direction in which the bar magnet stops, (ie., a line parallel to the bar magnet)
4. Turn the magnet gently and let it come to stop again.
5. Repeat it three or four times. The magnet always comes to rest in north-south direction.

VI. Questions based on higher-order thinking skills:

Question 1.
When iron needle is rubbed with bar magnet the needle get magnetized. But rubber piece is rubbed with magnet it will not get magnetized. Why?
Answer:
Because rubber is a non-magnetic substance.

Question 2.
What will happen when we place magnets near cell phone, computer and DVD?
Answer:

1. Magnets will lose their property.
2. These objects also will get affected.

Students can download 6th Science Term 2 Chapter 7 Parts of Computer Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 7 Parts of Computer

Samacheer Kalvi 6th Science Parts of Computer Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
Which one of the following is an output device?
(a) Mouse
(b) Keyboard
(c) Speaker
(d) Pen drive
Answer:
(c) Speaker

Question 2.
Name the cable that connects CPU to the Monitor
(a) Ethernet
(b) VGA cable
(c) HDMI
(d) USB
Answer:
(b) VGA cable

Question 3.
Which one of the following is an input device?
(a) Speaker
(b) Keyboard
(c) Monitor
(d) Printer
Answer:
(b) Keyboard

Question 4.
Which one of the following is an example for wireless connections?
(a) Wi-Fi
(b) Electric wires
(c) VGA
(d) USB
Answer:
(a) Wi-Fi

Question 5.
Pen drive is ……… device.
(a) Output
(b) Input
(c) Storage
(d) Connecting cable
Answer:
(c) Storage

II. Match the following

Answer:
1. – Connecting Cable
2. – wireless connection
3. – Output device
4. – Input device
5. – LDMI

III. Give Short Answer:

Question 1.
Name the parts of a computer.
Answer:
The computer has three parts like,
1. Input unit
2. Central Processing Unit
3. Output

Question 2.
Answer:

Activity

Look at the magic of connecting cables to desktop computer with 4,3,2,1 formula, start from 4 proceed till 1. Now your computer is ready to use.

By connecting the various parts of a computer we can assemble a computer. For the construction activity, students have to use 4-3-2-1 formula.

A system consist of mouse, key board, monitor, CPU, power cables, and connecting cables Students has to connect the four parts of a computer in row 4, using the cables in row 3, through the power cables in row 2 to construct a system.

Samacheer Kalvi 6th Science Parts of Computer Additional Important Questions and Answers

I. Choose the correct Answer:

Question 1.
Which one of the following is not important part of computer?
(a) Input device
(b) Output device
(c) Mouse
(d) Central Processing Unit
Answer:
(c) Mouse

Question 2.
The page on the monitor can be moved up and down using the _______
(a) Right button
(b) Scroll ball
(c) Left button
(d) Number key
Answer:
(b) Scroll ball

Question 3.
Which one of the following is an example for wireless connection.
(a) USB
(b) power cord
(c) HDMI
(d) wi-fi
Answer:
(d) wi-fi

Question 4.
The data is measured in units which is called as _______
(a) micron
(b) meter
(c) millimeter
(d) Bit
Answer:
(d) Bit

II. Fill in the Blanks

1. ………, ……….. plays a role of data in computer.
2. …….. controls the functions of all parts of the computer.
3. Memory unit divided into ………. types.
4. The data is measured in units which is called as ………..
5. Mouse is connected with the computer using ………..

Answer:

1. Numbers and alphabets
2. control unit
3. 2
4. Bit
5. USB cord or cable

III. Match the following

Answer:
1. – c
2. – d
3. – a
4. – e
5. – b

Students can download 6th Science Term 2 Chapter 6 Human Organ Systems Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 6 Human Organ Systems

Samacheer Kalvi 6th Science Human Organ Systems Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
The circulatory system transports these throughout the body
(a) Oxygen
(b) Nutrient
(c) Hormones
(d) All of these
Answer:
(d) All of these

Question 2.
Main organ of respiration in human body is
(a) Stomach
(b) Spleen
(c) Heart
(d) Lungs
Answer:
(d) Lungs

Question 3.
Breakdown of food into smaller molecules in our body is known as
(a) Muscle contraction
(b) Respiration
(c) Digestion
(d) Excretion
Answer:
(a) Digestion

II. Fill in the Blanks

1. A group of organs together make up an ………. system.
2. The part of the skeleton that protects the brain is …………
3. The process by which the body removes waste is ………..
4. The ………. is the largest sense organ in our body.
5. The endocrine glands produce chemical substances called …………

Answer:

1. Organ
2. Skull
3. Excretion
4. Skin
5. hormones

III. True or False. If False, give the correct answer.

1. Blood is produced in the bone marrow.
2. All the waste products of the body are excreted through the circulatory system.
3. The other name of the food pipe is an alimentary canal.
4. Thin tube-like structures which are the component of the circulatory system are called blood vessels.
5. The brain, the spinal cord, and nerves form the nervous system.

Answer:

1. False – RBC’s are produced in the bone marrow.
2. False – All the waste products are transported through the circulatory system.
3. False – The other name of the digestive tract is an alimentary canal.
4. True
5. True

IV. Match the following

Answer:
1. – c
2. – e
3. – b
4. – a
5. – d

V. Arrange in the correct sequence

Question 1.
Stomach → Large intestine → Oesophagus → Pharynx → Mouth → Small Intestine → Rectum → Anus
Answer:
Mouth → Pharynx → Oesophagus → Stomach → Small intestine → Large intestine → Rectum

Question 2.
Urethra → Ureter → Urinary Bladder → Kidney
Answer:
Kidney → Ureter → Urinary bladder → Urethra

VI. Analogy

1. Arteries : Carry blood from the heart:: ……….. : Carry blood to the heart.
2. Lungs : Respiratory system :: ……….. : Circulatory system.
3. Enzymes : Digestive glands :: ………… : Endocrine glands

Answer:

1. Veins
2. Heart
3. Hormones

VII. Give a Very short answer:

Question 1.
Describe the skeletal system.
Answer:

1. The skeletal system consists of bones, cartilages and joints.
2. Bones provide a framework for the body.
3. Bones along with muscles help in movements such as walking, running, chewing and dancing etc.

Question 2.
Write the functions of epiglottis?
Answer:

1. It prevents the entry of food into the windpipe.
2. It opens when the air enters the windpipe.

Question 3.
What are the three types of blood vessels?
Answer:

1. Arteries
2. Veins
3. Capillaries

Question 4.
Define the term “Trachea”
Answer:

1. The trachea commonly called “Windpipe” is a tube supported by cartilaginous rings.
2. It connects the pharynx and larynx to the lungs.
3. Allowing the passage of air.

Question 5.
Write any two functions of the digestive system.
Answer:

1. The digestive system is involved in the conversion of complex food substances into simple forms.
2. Absorption of digested food.

Question 6.
Name the important parts of the eye?
Three main parts.
Answer:

1. Cornea
2. Iris
3. Pupil

Question 7.
Name the five important sense organs.
Answer:

1. Eyes
2. Ears
3. Nose
4. Tongue
5. Skin

VIII. Give a short answer:

Question 1.
Write a short note on the rib cage.
Answer:

1. The rib cage is made up of 12 pairs of curved, flat rib bones.
2. It protects the delicate vital organs such as the heart and lungs.

Question 2.
List out the functions of the human skeleton.
Answer:

1. The skeletal system gives shape to the body.
2. Bones provide a framework for the body.
3. Bones along with muscles help in movements such as walking, running, chewing and dancing, etc.
4. It protects the soft internal organs.

Question 3.
Differentiate between the voluntary muscles and involuntary muscles.
Answer:

IX. Answer in detail:

Question 1.
List out the functions of the Endocrine system and Nervous system.
Answer:

1. Endocrine system regulates various functions of the body and maintains the internal environment.
2. Endocrine glands produce chemical substances called “Hormones’ which control various activities of the body.
   Eg. Growth hormone controls growth, the Adrenalin hormone acts at the time of fear stress, etc.

Functions of the nervous system:

1. Sensory input: The conduction of signals from sensory receptors.
2. Integration: The interpretation of the sensory signals and the formulation of responses.
3. Motor output: The conduction of signals from the brain and spinal card to effectors such as muscle and gland cells.

Question 2.
Label the diagram given below to show the four main parts of the urinary system and answer the following questions.

a. Which organ removes extra salts and water from the blood?
b. Where is the urine stored?
c. What is the tube through which urine is excreted out of the body?
d. What are the tubes that transfer urine from the kidneys to the urinary bladder called?
Answer:
a. The functional units of the kidney are called Nephrons which filter the blood and form the urine.
b. Urine is stored in the urinary bladder.
c. Urine is expelled out through the urethra.
d. The ureters that transfer urine from the kidneys to the urinary bladder.

X. Questions based on Higher Order Thinking Skills

Question 1.
What will happen if the diaphragm shows no movement?
Answer:

1. The diaphragm is the primary organ of breathing.
2. The movement of the diaphragm expands the lungs and creates a vacuum.
3. Due to this, the air is sucked in.
4. If the diaphragm does not move the lungs do not expand or contract and breathing stops.
5. The person will die.

Question 2.
Why is the heart divided into two halves by a thick muscular wall?
Answer:

1. The ventricles of the heart have thicker muscular walls than the atria.
2. The left ventricle also has a thicker muscular wall than the right ventricle.
3. This is due to the higher forces needed to pump blood through the systemic circuit compared to the pulmonary circuit.

Question 3.
Why do we sweat more in summer?
Answer:

1. Sweating plays an important health role as it helps to maintain constant body temperature by cooling us down.
2. When it is hot and we sweat that moisture evaporates and cools us immediately.
3. This is why we sweat more when the summer is very hot.

Question 4.
Why do we hiccup and cough sometimes when we swallow food?
Answer:
Reasons for hiccup and cough :

1. Eating too – quickly and swallowing air along with foods.
2. Eating too – many fatty or spicy foods in particular.
3. Drinking too much-carbonated beverages or alcohol can distend the stomach and irritate the diaphragm which can cause hiccups.

Samacheer Kalvi 6th Science Human Organ Systems Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
A newborn baby has ……….. bones.
(a) 206
(b) More than 200
(c) More than 300
(d) 210
Answer:
(c) More than 300

Question 2.
_______ connect bone to muscle.
(a) Skeleton
(b) Tendons
(c) Cartilages
(d) Ligaments
Answer:
(b) Tendons

Question 3.
The walls of the heart is made up of
(a) Voluntary muscles
(b) Cardiae muscles
(c) Involuntary muscles
(d) Biceps muscle
Answer:
(b) Cardiac muscles

Question 4.
_______ muscles are found in the walls of the digestive tract, urinary bladder arteries, and other internal organs.
(a) Bone
(b) Smooth
(c) Cardiac
(d) triceps
Answer:
(b) Smooth

Question 5.
The bronchi divide further and end in small air sacs called
(a) Cerebrum
(b) Thymus
(c) Alveoli
(d) Pinna
Answer:
(c) Alveoli

II. Fill in the blanks:

1. The adult human skeletal system consists of 206 bones and a few ………., ……… and ………..
2. The brain is covered by a three-layered tissue covering called………..
3. When we are walking, running or climbing the balance of the body is maintained by ………….
4. The endocrine gland present in the chest is …………..
5. The ………. brings blood containing oxygen and urea from the aorta to the kidneys.
6. connects the brain to a different part of the body through nerves.

Answer:

1. cartilages, ligaments, and tendons
2. meninges
3. Ears
4. Thymus Gland
5. renal artery
6. spinal cord

III. Match the Following:

Answer
1. – iii.
2. – i.
3. – iv.
4. – v.
5. – ii.

IV. Arrange in the correct sequence

Question 1.
Trachea → Bronchi → Pharynx → Lungs → Larynx → Nasal cavity → Nostrils → Bronchiole → Alveolus
Answer:
Nostrils → Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchiole → Alveolus

Question 2.
Middle ear → Pinna → Outer ear → Inner ear
Answer:
Pinna → Outer ear → Middle ear → Inner ear.

V. Analogy

1. Skull: Made up of cranial bones and facial bones :: ………… : Made up of 12 pairs of curved flat rib bones
2. Biceps : Bends the arm at the elbow :: ……….. : Straightens the elbow

Answer:

1. Ribcage
2. Triceps

VI. Very Short Answer:

Question 1.
What are the two major divisions of the skeletal system?
Answer:
The two major divisions of the skeletal system are.

1. Axial skeleton
2. Appendicular skeleton.

Question 2.
Name the auditory ossicles.
Answer:

1. Malleus
2. Incus
3. Stapes

Question 3.
Which is the longest bone in our body?
Answer:
The thigh bone (femur) is the longest bone.

Question 4.
What is the name of the muscles in the heart?
Answer:
Cardiac muscle.

Question 5.
What is the length of the Alimentary canal?
Answer:
9 metres.

VII. Answer in detail:

Question 1.
Tabulate the differences between arteries and veins.
Answer:
Arteries:

1. Carry blood from the heart to all parts of the body.
2. Carry oxygenated blood (Except pulmonary artery).
3. They have thick elastic muscular walls.
4. Valves are absent.
5. Blood flows under high pressure.

Veins:

1. Carry blood from all parts of the body back to the heart.
2. Carry deoxygenated blood (Except pulmonary vein).
3. They have thin non-elastic valves.
4. Valves are present to prevent the backward flow of blood.
5. Blood flows under low pressure.

Question 2.
Differentiate arteries from a vein and tabulate your answer.
Answer:

Students can download 6th Science Term 2 Chapter 5 The Cell Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 5 The Cell

Samacheer Kalvi 6th Science The Cell Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
The unit of measurement used for expressing dimension (size) of cell is
(a) centimeter
(b) millimeter
(c) micrometer
(d) meter
Answer:
(c) micrometer

Question 2.
Under the microscope, Priya observes a cell that has a cell wall and a distinct nucleus. The cell that she observed is
(a) a plant cell
(b) an animal cell
(c) a nerve cell
(d) a bacteria cell
Answer:
(d) a bacteria cell

Question 3.
A ‘control centre’ of the eukaryotic cell is
(a) Cell wall
(b) Nucleus
(c) Vacuoles
(d) Chloroplast
Answer:
(b) Nucleus

Question 4.
Which one of the following is not a unicellular organism?
(a) Yeast
(b) Amoeba
(c) Spirogyra
(d) Bacteria
Answer:
(c) Spirogyra

Question 5.
Most organelles in a eukaryotic cell are found in the
(a) Cell wall
(b) cytoplasm
(c) nucleus
(d) Vacuole
Answer:
(b) cytoplasm

II. Fill in the Blanks

1. The instrument used to observe the cell is ………..
2. I control the food production of a cell. Who am I? ………..
3. I am like a policeman. Who am I ………?
4. The Term “cell” was coined by ………..
5. The egg of an Ostrich is the ……….. single cell.

Answer:

1. Microscope
2. Chloroplast
3. Cell membrane
4. Robert Hooke
5. Largest

III. True or False. If False, give the correct answer.

1. A cell is the smallest unit of life.
2. Nerve cell is the longest cell
3. Prokaryotes were the first form of life on earth.
4. The organelles of both plants and animals are made up of cells. (Organelles – Found inside the cell)
5. New cells are produced from existing cells.

Answer:

1. True
2. True
3. True
4. False
5. True

IV. Match the following

Answer:
1. – c
2. – d
3. – e
4. – a
5. – b

V. Arrange in a correct sequence

Question 1.
Elephant, Cow, Bacteria, Mango, Rose plant.
Answer:
Bacteria, Mango, Rose plant, Cow, Elephant.

Question 2.
Hen Egg, Ostrich egg, Insect egg.
Answer:
Insect egg, Hen egg, Ostrich egg

VI. Analogy

1. Prokaryote : Bacteria :: Eukaryote : ………..
2. Spirogyra : Plant cell :: Amoeba : ………….
3. Food producer : Chloroplasts :: Power house : …………

Answer:

1. Plants, Animals
2. Animal cell
3. Mitochondria

VII. Give a Very short answer:

Question 1.
Who discovered the cell in 1665?
Answer:
The English scientist Robert Hooke discovered the cell in 1665 from cork slices kept under a microscope.

Question 2.
What type of cells do we have?
Answer:
We have a Eukaryotic type of cells.

Question 3.
What are the essential components of a cell?
Answer:
A typical cell consists of three major parts.

1. An outer cell membrane
2. A liquid cytoplasm
3. Nucleus

Question 4.
What are the organelles found only in plant cells?
Answer:

1. Cell wall
2. Chloroplast

Question 5.
Give any three examples of eukaryotic cells.
Answer:

1. Plant cells
2. Animal cells
3. Most of fungi and Algae

Question 6.
Which one is called as “Area of movement”?
Answer:
The cytoplasm is a watery, gel-like material in which cell parts move. So it is known as an “Area of movement”.

Question 7.
Shiva said, “Bigger onion has larger cells when compared to the cells of the smaller onion”! Do you agree with his statement or not? Explain why?
Answer:
No, the big onion and small onion both of them have plant cell and the size of every cell remains the same whether it is of a small onion or big one. The shape is larger means that the number of cells is more in bigger onion.

VIII. Give a short answer:

Question 1.
Why cells are called building blocks of life?
Answer:
A brick is a basic building block of a wall, likewise, the cells are the basic structural and functional unit of every living organism. So the cells are called as building blocks of life.

Question 2.
Identify any four parts of the plant cell?

Answer:
A – Cell Wall,
B – Cytoplasm,
C – Nucleus,
D – Mitochondria

Question 3.
Distinguish between prokaryotic and eukaryotic cells
Answer:

Question 4.
Make sketches of animal and plant cells which you observe under the microscope.
Answer:

Cell Wall & Chloroplasts – Absent in Animal Cells
Centrioles – Absent in Plant Cells

Question 5.
Write about the contribution of Robert Hooke in cell biology
Answer:
Robert Hooke was a scientist and inventor. He improved the microscope and built a compound microscope. One day he made thin sections of the cork and observed many small identical chambers through his microscope. They were hexagonal in shape. Based on these observations Hooke published a book named Micrographia in the year 1665, where he first used the term Cell. He describes the structure of tissue using the term cell.

IX. Answer in detail:

Question 1.
Tabulate any five cell organelles and their function.
Answer:

Question 2.
Draw a neat labelled diagram of a prokaryotic cell.
Answer:

X. Project (For Students)

Question 1.
Use your imagination and create a 3-D model of a plant cell?

Question 2.
You can use numerous food materials such as jelly and some cake to make a cell body. Cell organelles can be made using nuts and dry fruits. You can display the model in your classroom and invite teachers or students from other classes to rise questions on the project and try to give answers.

Samacheer Kalvi 6th Science The Cell Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
The first cell formed in the earth
(a) Eukaryotic cell
(b) Algal cell
(c) Fungal cell
(d) Prokaryotic cell
Answer:
(d) Prokaryotic cell

Question 2.
Robert Hooke published a book named ______ in the year 1665.
(a) Cellula
(b) Micrographia
(c) Cell biology
(d) Organelles
Answer:
(b) Micrographia

Question 3.
The pigment present in leaf to absorb light is
(a) chlorophyll
(b) chloroplast
(c) chromoplast
(d) leucoplast
Answer:
(a) chlorophyll

Question 4.
The largest cell is the egg of an ______ with 170-millimeter width.
(a) Ostrich
(b) viper
(c) tortoise
(d) Hen
Answer:
(a) Ostrich

II. Assertion and Reason

Question 1.
Assertion (A) : Chloroplast is a cell organelle
Reason (R) : An organelle is a distinct part of the cell which has a particular structure and Function.
(a) Assertion (A) and Reason R – True and R is the correct explanation of A
(b) Both A and R – true but R is not the correct explanation of A
(c) A True but R False
(d) A False but R True
Answer:
(a) Assertion (A) and Reason R – True and R is the correct explanation of A

Question 2.
Assertion (A) : Mitochondria is an important organ cell of the cell
Reason (R) : Mitochondria is involved in food preparation
(a) Assertion (A) and Reason R – True and R is the correct explanation of A
(b) Both A and R – true but R is not the correct explanation of A
(c) A True but R False
(d) A False but R True
Answer:
(c) A True but R False

III. Match the Following:

Answer:
1. – B
2. – D
3. – E
4. – C

IV. Very Short Answer:

Question 1.
Arrange the following cells in the order of their size.
(a) Bacteria cell
(b) Frogs egg
(c) Hen’s egg
(d) Human egg.
Answer:
(a) Bacterial cell
(b) Human egg
(c) Frogs egg
(d) Hen’s egg

Question 2.
How do you distinguish between living and dead cells?
Answer:
Living cells have a nucleus (Eg.) Onion peel cells.
Non-Living cells don’t have a nucleus (Eg.) Cork ceils.

Question 3.
Name the largest Angiosperm cell
Answer:
The largest Angiosperm cell is citrus reticulata (clearly visible in orange pulp) & citrus maxima.

Question 4.
Name the organelle without membrane.
Answer:
Ribosomes are the cell organelle in which the membrane is absent.

Question 5.
Identify the following diagram and label A, B, C, D

Answer:
The diagram is the structure of the chloroplast
A – outer membrane
B – inner membrane
C – Thylakoid
D – stroma

Question 6.
Identify the following diagram and label A, B, C

Answer:
A – Outer Membrane
B – Cristae
C – Matrix

Question 7.
Identify the following diagram and label A, B, C

Answer:
Structure of Nucleus
A – Nuclear membrane
B – Nuclear pore
C – Nucleolus
D – Chromatin reticulum

Students can download 6th Science Term 2 Chapter 2 Electricity Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 2 Electricity

Samacheer Kalvi 6th Science Electricity Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
The device which converts chemical energy into electrical energy is
(a) fan
(b) solar cell
(c) cell
(d) television
Answer:
(c) cell

Question 2.
Electricity is produced in
(a) transformer
(b) power station
(c) electric wire
(d) television
Answer:
(b) power station

Question 3.
Choose the symbol for battery

Answer:

Question 4.
In which among the following circuits does the bulb glow?

Answer:

Question 5.
_______ is a good conductor
(a) silver
(c) rubber
(b) wood
(d) plastic
Answer:
(a) silver

II. Fill in the Blanks

1. ………. are the materials which allow electric current to pass through them.
2. Flow of electricity through a closed circuit is …………
3. ……… is the device used to close or open an electric circuit.
4. The long perpendicular line in the electrical symbol represents its ………… terminal.
5. The combination of two or more cells is called a ………..

Answer:

1. Conductors
2. electric current
3. Key
4. positive
5. battery

III. True or False. If False, give the correct answer.

1. In a parallel circuit, the electricity has more than one path.
2. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell.
3. The switch is used to close or open an electric circuit.
4. Pure water is a good conductor of electricity.
5. Secondary cell can be used only once.

Answer:

1. True
2. False – The negative terminal of one cell is connected to positive terminal of other cell.
3. True
4. False – Pure water is an insulator.
5. False – Secondary cells can be used many times.

IV. Match the following

Answer:
1. – Battery
2. – Bulb does not glow
3. – Open key
4. – Bulb glows
5. – Cell

V. Arrange in Sequence

Answer:
A DEVICE THAT CONVERTS CHEMICAL ENERGY INTO ELECTRICAL ENERGY IS CALLED A CELL.

VI. Give Very Short Answers

Question 1.
In the given circuit diagram, which of the given switches) should be closed. So that only the bulb A glows.

Answer:
K₁ and K₂ should be connected to glow bulb A in the circuit

Question 2.
Assertion (A) : It is very easy for our body to receive electric shock.
Reason (R) : Human body is a good conductor of electricity.
a. Both A and R are correct and R is the correct explanation for A.
b. A is correct, but R is not the correct explanation for A.
c. A is wrong but R is correct.
d. Both A and R are correct and R is not the correct explanation for A.
Answer:
(a) Both A and R are correct and R is the correct explanation for A.

Question 3.
Can you produce electricity from a lemon?
Answer:

1. We can produce electricity from the lemon.
2. Take lemon as an electrolyte, copper plate as positive terminal, and small hairpin as the negative terminal. This setup will work as a cell.
3. If we connect the electric bulb with it bulb will glow.

Question 4.
Identify the conductor from the following figures.

Answer:
Metallic chain is a conductor.

Question 5.
What type of circuit is there in a torchlight?
Answer:
Simple circuit system is used in a torchlight.

Question 6.
Circle the odd one out. Give a reason for your choice.
Answer:
Switch, Bulb, Battery, Generator.
Generator is the source of electricity. Others are parts of a circuit.

VII. Give Short Answers:

Question 1.
Draw the circuit diagram for the series connection.
Answer:

Question 2.
Can the cell used in the clock give us an electric shock? Justify your answer.
Answer:

1. The cell used in the clock will not give us an electric shock because the voltage of that cell is very low nearly 1.5 v.
2. So it will not affect our body.

Question 3.
Silver is a good conductor but it is not preferred for making electric wires. Why?
Answer:

1. Silver is a costly metal.
2. So economically we can not use it in electric wires.

VIII. Answer in detail:

Question 1.
What is the source of electricity? Explain the various power stations in India.
Answer:

1. In thermal power stations, thermal energy is generated by burning coal, diesel, or gas to produce steam.
2. Steam is used to rotate the turbine to generate electricity.
3. Here heat energy is converted into electric energy.

Hydel power stations:

1. In hydel power stations, the turbine is made to rotate by the flow of water from dams.
2. Here kinetic energy is converted into electric energy.

Atomic power station:

1. Here nuclear energy is used to boil water
2. The steam thus produced is used to rotate the turbine, as a result, electricity is produced.
3. Here nuclear energy is converted into mechanical energy.

Windmills:

1. In windmills, wind energy is used to rotate turbines to produce electricity.
2. Here kinetic energy is converted into electrical energy.

Question 2.
Tabulate the different components of an electric circuit and their respective symbols.
Answer:

Question 3.
Write short notes on conductors and insulators.
Answer:
Conductors:
The rate of flow of electric charges in a circuit is called electric current. The materials which allow electric charges to pass through them are called conductors.
Examples: Copper, iron, aluminum, impure water, earth, etc.,

Iniulaton (Non-Conductors):
The materials which do not allow electric charges to pass through them are called insulators or non-conductors.
Examples: plastic, glass, wood, rubber, china clay, ebonite, etc.

IX. Questions Based on Higher Order Thinking Skills

Question 1.
Rahul wants to make an electric circuit. He has a bulb, two wires, a safety pin, and a piece of copper. He does not have any electric cell or battery. Suddenly he gets some idea. He uses lemon instead of a battery and makes a circuit. Will the bulb glow?
Answer:
1. Yes, the bulb will glow.
2. Insert a piece of copper on one side of lemon, safety pin on another side. This system will work as a battery.
3. Copper rod – Positive terminal
Safety pin – Negative terminal, Lemon – Electrolyte
4. Connect the connecting wire in both the terminals and finally connect to the bulb.
5. The current produced is passed through the circuit and the bulb will glow.

X. Search ten words in the given word grid and classify them as conductors and insulators

Question 1.

Answer:

Samacheer Kalvi 6th Science Electricity Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
Here heat energy is converted into electric energy
(a) Thermal power station
(b) Atomic power station
(c) Hydel power station
(d) Windmills
Answer:
(a) Thermal power station

Question 2.
In atomic power station, ________ is used to rotate the turbine.
(a) water
(b) steam
(c) Air
(d) diesel
Answer:
(b) steam

Question 3.
Which one of the following is using secondary using cells?
(a) Hand watch
(b) Robo toy
(c) Laptop
(d) None of these
Answer:
(c) Laptop

Question 4.
If two or more ________ are connected in series in a circuit, then it is called a series circuit.
(a) keys
(b) cells
(c) connecting wires
(d) bulbs
Answer:
(d) bulbs

Question 5.
……….. fish is able to produce an electric current.
(a) Goldfish
(b) Electric Eel
(c) Katla
(d) Salamon fish
Answer:
(b) Electric Eel

II. Fill in the blanks:

1. Any device from which electricity is produced is called ………..
2. The place in Kanyakumari district that has more windmills is ………..
3. ……….. have long economic lives and low operating cost.
4. A chemical solution that produces positive and negative ions is used as ………….
5. ……….. invented the electric bulb.

Answer:

1. Source of electricity
2. Aralvaimozhi
3. Hydel power stations
4. electrolyte
5. Thomas Alva Edison

III. Say True of False.

1. Atomic power stations convert nuclear energy into electric energy.
2. The cell can be used only once is called secondary cells.
3. We can produce electricity from potatoes.
4. An ammeter is connected in parallel in circuits.
5. The voltage of the torchlight battery is 1.5 v.

Answer:

1. True
2. False
3. 3. True
4. False
5. True

IV. Match the Following:

Answer:
1. – iii
2. – i
3. – iv
4. – ii
5. – v

V. Assertion and Reason

Question 1.
Assertion (A) : Experiments with electricity should only be performed with torch or radio batteries.
Reason (R) : Household electric supply will have high voltage and dangerous
a. Both A and R are correct and R is the correct explanation for A.
b. A is correct, but R is not the correct explanation for A.
c. A is wrong but R is correct.
d. Both A and R are correct and R is not the correct explanation
Answer:
a. Both A and R are correct and R is the correct explanation for A.

Question 2.
Assertion (A) : Primary cells can not be recharged, they can be used only once.
Reason (R) : In vehicles, we use primary cells.
a. Both A and R are correct and R is the correct reason for A.
b. A is true but R is not correct.
c. Both A and R are correct, but R is not the correct reason for A
d. A is not correct but R is correct
Answer:
b. A is true but R is not correct

VI. Very Short Answer:

Question 1.
What are the places in which atomic power stations located in Tamil Nadu?
Answer:

1. Kalpakkam, Kanchipuram district.
2. Koodankulam, Tirunelveli district.

Question 2.
List out the parts required to make an electric circuit
Answer:
A key, connecting wires, dry cell or battery, and electric bulb.

Question 3.
How to connect the cells in torchlight to glow bulbs?
Answer:
1. Connect the positive terminal of one cell with the negative terminal of another cell.
2. The bulb will glow.

Question 4.
How electric current is produced in Thermal power stations?
Answer:
The thermal energy generated by burning coal is used to produced steam. The steam thus produced is used to rotate the turbine. While the turbine rotates, the coil of wire kept between the electromagnet rotates. Due to electromagnetic induction, electricity is produced.

Question 5.
What is meant by a battery or collection of cells?
Answer:
Two or more cells are combined together to make a battery or collection of cells.

VII. Long Answer Questions:

Question 1.
What is a cell? Explain the types of cells.
Answer:
A device that converts chemical energy into electrical energy is called a cell. Cells are classified, in two types. They are-

1. Primary cells,
2. Secondary cells.

1. Primary cells:

• They can not be recharged.
• They can be used only once.
• They are small in size.
• Eg. Cells used in clocks, watches, and toys, etc.

2. Secondary cells:

• A cell that can be recharged many times is called secondary cells.
• Depending upon usage size may vary.
• Eg. Secondary cells are used in mobile phones, laptops, emergency lamps, and vehicle batteries.

Question 2.
What are the safety measures to safeguard a person from electric shock?
Answer:
Safety measures to safeguard a person from electric shock:

1. Switch off the power supply.
2. Remove the connection from the switch.
3. Push him away using non-conducting materials.
4. Give him first aid and take him to the nearest health centre.

Students can download 6th Science Term 2 Chapter 4 Air Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 4 Air

Samacheer Kalvi 6th Science Air Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
……… is the percentage of nitrogen in the air.
(a) 78%
(b) 21%
(c) 0.03%
(d) l%
Answer:
(a) 78%

Question 2.
Gas exchange takes place in plants using _______
(a) Stomata
(b) Chlorophyll
(c) Leaves
(d) Flowers
Answer:
(a) Stomata

Question 3.
The constituent of air that supports combustion is ……….
(a) Nitrogen
(b) carbon-di-oxide
(c) Oxygen
(d) water vapour
Answer:
(c) Oxygen

Question 4.
Nitrogen is used in the food packaging industry because it _______
(a) provides colour to the food
(b) provides oxygen to the food
(c) adds proteins and minerals to the food
(d) keeps the food fresh
Answer:
(d) keeps the food fresh

Question 5.
……… and ………… are the two gases, which when taken together, make up about 99 percentage of air.
I. Nitrogen
II. carbon-di-oxide
III. Noble gases
IV. Oxygen
(a) I and II
(b) I and III
(c) II and IV
(d) I and IV
Answer:
(d) I and IV

II. Fill in the blanks

1. …………. is the active component of air.
2. The gas given out during photosynthesis is ………..
3. ………. gas is given to the patients having breathing problems.
4. ………. can be seen moving in a beam of sunlight in a dark room.
5. …………. gas turns lime water milky.

Answer:

1. Oxygen(O₂)
2. Oxygen(O₂)
3. Oxygen (O₂)
4. Tiny dust particles
5. Carbon dioxide (CO₂)

III. True or False. If False, give the correct statement

1. Inhaled air contains a large amount of carbon-di-oxide
2. Planting trees help in decreasing global warming
3. The composition of air is always exactly the same.
4. Whales come up to the water surface to breathe in oxygen.
5. The balance of oxygen in the atmosphere is maintained through photosynthesis in animals and respiration in plants.

Answer:

1. False – (Inhaled air contains a large amount of oxygen)
2. True
3. False – (The composition of air changes slightly from place to place & also from season to season)
4. True
5. False – (The balance of oxygen in the atmosphere is maintained through Photosynthesis in plants & respiration in animals)

IV. Match the following

Answer:
1. – c
2. – b
3. – d
4. – e
5. – a

V. Arrange the following statements in correct sequence

1. Plants manufacture food by a process called photosynthesis.
2. Plants require energy for their growth.
3. Plants take in oxygen and release carbon-di-oxide just as animals.
4. Plants take carbon-di-oxide from the atmosphere, use chlorophyll in the presence of sunlight and prepare food.
5. Such oxygen is available to animals and human beings for breathing.
6. During this process, oxygen is released by plants.
Answer:
2. Plants require energy for their growth.
1. Plants manufacture food by a process called photosynthesis.
6. During this process, oxygen is released by plants.
3. Plants take in oxygen and release carbon-di-oxide just as animals.
5. Such oxygen is available to animals and human beings for breathing.
4. Plants take carbon-di-oxide from the atmosphere, use chlorophyll in the presence of sunlight and prepare food.

VI. Analogy

Question 1.
Photosynthesis: ……….. ::
Respiration : Oxygen
Answer:
CO₂

Question 2.
78% of air : Does not support combustion ::
……… : Supports combustion
Answer:
21% of air

VII. Observe the given figure carefully and answer the questions.

Question 1.
What will happen if we remove plants from the aquarium?
Answer:

1. The production of O₂ and absorption of CO₂ and NH₃ will you reduced.
2. Plants provide shelter to fish, so, they feel insecure.
3. Algae growth will increase.

Question 2.
What will happen if we remove the fish from the aquarium and keep it (with green plants) in a dark place?

Answer:

1. Most of the fishes require both periods of light and darkness.
2. In a dark place, they will loose their sight and pigmentation.

VIII. Give a very short Answer

Question 1.
What is the atmosphere? Name the five layers of the atmosphere.
Answer:
Our earth is surrounded by a huge envelope of air called the atmosphere.
The atmosphere is made of five different layers – the Troposphere, the Stratosphere, the Mesosphere, the Ionosphere, and the Exosphere.

Question 2.
How do the roots of land plants get oxygen for breathing?
Answer:
Oxygen is present in the air spaces of soil. This O₂ is taken by root hairs through diffusion to the rest of the plant.

Question 3.
What should be done if the clothes of a person catch fire accidentally? Why?
Answer:

1. Cover the person in a rug or blanket and Roll him on the floor.
2. This will cut off the air and put out the flames.
3. A suitable fire extinguisher can also be chosen.

Question 4.
What will happen if you breathe through your mouth?
Answer:
Several health conditions and risk factors can lead to mouth breathing.

1. Snoring
2. dry mouth
3. daytime tired
4. Poor dental health

IX. Give a short answer

Question 1.
Biscuits kept open on a plate during monsoon days lose their crispness. Why?
Answer:
During monsoon days, Water vapour from the atmosphere is absorbed in the biscuits. So the biscuits lose its crispness.

Question 2.
Why do traffic assistants wear a mask on duty?
Answer:
Traffic assistants are continually exposed to smoke emitted out from the vehicles. Inhaling the pollutants in the smoke may cause breathing and lung problems. So they wear a mask on duty.

X. Answer in detail

Question 1.
How do plants and animals maintain the balance of oxygen and carbon-di¬oxide in air?
Answer:

1. plants in forests release oxygen through the process of photosynthesis and help in providing oxygen to animals for respiration.
2. Plants consume carbon dioxide released by the animals. In this way, plants help in maintaining a balance of oxygen and carbon dioxide in the atmosphere.

Question 2.
Why is the atmosphere essential for life on earth?
Answer:

The atmosphere is essential for life because it maintains an appropriate climate for the maintenance of life by carrying out the following activities:

1. The atmosphere keeps the average temperature of the Earth fairly constant during the day time.
2. It prevents a sudden increase in temperature during the day time.
3. It also slows down the escape of heat from the surface of the Earth into outer space during the night time.

XI. Questions Based on Higher Order Thinking Skills.

Question 1.
Can you guess why fire extinguishers throw a stream of carbon-di-oxide while putting – off fire?
Answer:
It is because carbon-di-oxide (CO₂) does not support combustion. When sprayed on burning object it stops the supply of oxygen and controls the fire.

Samacheer Kalvi 6th Science Air Additional Important Questions and Answers

I. Choose the appropriate answer

Question 1.
A layer consisted of water vapour which is responsible for making clouds is.
(a) Stratosphere
(b) Mesosphere
(c) Troposphere
(d) Exosphere
Answer:
(c) Troposphere

Question 2.
_______ is responsible for making clouds.
(a) Hydrogen
(b) Oxygen
(c) Water vapour
(d) Carbon-di-oxide
Answer:
(c) Water vapour

Question 3.
A process without emitting flame is called as …………
(a) Combustion
(b) Burning
(c) Cherring
(d) Melting
Answer:
(a) Combustion

Question 4.
_______ was able to identify highly reactive gas called oxygen.
(a) Lavoisier
(b) Ingenhousz
(c) Rutherford
(d) Joseph Priestley
Answer:
(d) Joseph Priestley

Question 5.
Which is used in refrigerating meat and fish?
(a) Liquid Ammonia
(b) Liquid Nitrogen
(c) Solid CO₂
(d) Helium
Answer:
(c) solid CO₂

II. True or False. If False, give the correct statement

1. Oxygen is used for the synthesis of protein and fertilizers.
2. CO₂ turns calcium hydroxide solution to a milky white solution.
3. The air in coastal areas have more oxygen.
4. The role of chlorophyll is to absorb light from the sun.
5. When cooled to -57°C, gaseous carbon-di-oxide becomes a liquid.

Answer:

1. False – (Nitrogen is used for the synthesis of protein and fertilizers)
2. True
3. False – (The air in coastal areas have more water vapour)
4. True
5. False – (When cooled to -57°C, gaseous carbon-di-oxide becomes a solid)

III. Match the following

Answer:
i. – c
ii. – d
iii. – a
iv. – b

IV. Give very short answer

Question 1.
Where does Ozone layer lie?
Answer:
Ozone layer is present in stratosphere lies above the troposphere.

Question 2.
“Air is not an elementary substance, but a composition”. Why?
Answer:
Air is a composite mixture of many gases like N₂, O₂, CO₂ and others.

Question 3.
Mention the percentage composition of Air.
Answer:

Question 4.
What is Burning?
Answer:
The process of firing of a substance in the presence of O₂ and releasing a large amount of light and heat.

Question 5.
Define – Combustion. Give an example.
Answer:
The process of firing which does not emit flame is called combustion (fire without flame). Ex: Rocket propellants (fuel with oxygen).

V. Answer in detail

Question 1.
Briefly explain the process of ‘Photo Synthesis’.
Answer:

1. Plants manufacture their food by ‘Photo Synthesis’.
2. CO₂ from the air and water from the solid react in the presence of sunlight to produce food.
   
3. Chlorophyll absorbs light from the sun.
4. The liberated O₂ during photosynthesis is much more than the O₂ consumed by the plants for respiration.

Question 2.
Mention the uses of Air.
Answer:

1. For breathing by plants and Animals.
2. For burning fuels like wood, coal, kerosene, LPG etc.,.
3. Compressed air is used to fill tyres of vehicles.
4. Maintaining the water cycle in nature. Because this air did not have O₂ and CO₂.
5. O₂ gas is used by patients in Hospitals, Climbers in mountains, Divers in Deepsea.

Students can download 6th Science Term 2 Chapter 3 Changes Around Us Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 3 Changes Around Us

Samacheer Kalvi 6th Science Changes Around Us Text Book Back Questions and Answers

I. Choose the Correct Answer

Question 1.
When ice melts to form water, change occurs in its
(a) position
(b) colour
(c) state
(d) composition
Answer:
(c) State

Question 2.
Drying of wet clothes in air is an example of
(a) Chemical change
(b) Undesirable change
(c) irreversible change
(d) physical change
Answer:
(d) Physical change

Question 3.
Drying of wet clothes in air Is an example of
(a) Chemical change
(b) Undesirable change
(c) irreversible change
(d) physical change
Answer:
(d) physical change

Question 4.
Out of the following an example of a desirable change ¡s
(a) rusting
(b) change of seasons
(c) earthquake
(d) flooding
Answer:
(b) change of seasons

Question 5.
Air pollution leading to Acid rain is a
(a) reversible change
(b) fast change
(c) natural change
(d) human made change
Answer:
(d) human made change

II. Fill in the blanks

1. Magnet attracts iron needle. This is ……… change, (a reversible / an irreversible)
2. Boiling of egg results in ………… change, (a reversible / an irreversible)
3. Changes that are harmful to us are ………… (desirable / undesirable)
4. Plants convert Carbon-di-oxide and water into starch. This is an example of ………. change, (natural / human made)
5. Bursting of fire crackers is a ……….. change whereas germination of seeds is a ………. change, (slow / fast)

Answer:

1. a reversible
2. an irreversible
3. undesirable
4. Natural
5. fast; slow

III. True or False. If False, give the correct statement

1. Growing of teeth in an infant is slow change.
2. Burning of match stick is a reversible change.
3. Change of New moon to Full moon is human made.
4. Digestion of food is a physical change.
5. In a solution of salt in water, water is the solute.

Answer:

1. True
2. False – It is an irreversible change
3. False – It is a Natural change
4. False – It is a Chemical change
5. False – Water is the solvent

IV. Analogy

Question 1.
Curdling of milk : irreversible change ::
Formation of clouds : ……….. change
Answer:
reversible

Question 2.
Photosynthesis : ……….. change ::
burning of coal : Human – made change
Answer:
Natural

Question 3.
Dissolving of glucose: reversible change ::
Digestion of food : ………… change
Answer:
Irreversible

Question 4.
Cooking of food : desirable change ::
decaying of food : ………… change
Answer: undesirable

Question 5.
Burning of matchstick: ………… change ::
Rotation of the Earth : Slow change
Answer:
Fast

V. Circle the odd one out. Give reason for your choice

Question 1.
Growth of a child, Blinking of eye, Rusting, Germination of a seed.
Answer:
Blinking of eye (a fast change)

Question 2.
Glowing of a bulb, lighting of a Candle, breaking of a coffee mug, curdling of milk.
Answer:
Curdling of milk (a chemical change)

Question 3.
Rotting of an egg, condensation of water vapour, trimming of hair, Ripening of fruit.
Answer:
Trimming of hair (Man-made change)

Question 4.
Inflating a balloon, popping a balloon, fading of wall paint, burning of kerosene
Answer:
Burning of Kerosene (Chemical change)

VI. Give a very short answer

Question 1.
What kind of change is associated with the decaying of plants?
Answer:
Decaying of plants is associated with slow change and chemical change.

Question 2.
You are given some candle wax. Can you make a candle doll from it? What kind of change is this?
Answer:
Yes, I can make a doll from the candle. The kind of change is a physical change.

Question 3.
Define a slow change.
Answer:
Changes which take place over a long period of time (hours/days/months/years) are known as slow changes.

Question 4.
What happens when cane sugar is strongly heated? Mention any two changes in it.
Answer:
When Cane sugar is strongly heated, it will initially melt and after that start to decompose. It will turn brown and then black and give off fumes.
The changes involved are:

1. Physical change
2. irreversible change

Question 5.
What is the solution?
Answer:
When a solute is dissolved in a solvent, it forms a solution.
Solute + solvent → solution.

VII. Give a short answer

Question 1.
What happens when the paper is burnt? Explain.
Answer:
When the paper is burnt, oxygen from the air combines with carbon in the paper turning into carbon dioxide and water vapor which float away, leaving solid ash. The action of burning paper can’t be reversed. So, it is an irreversible change. Also, it is a Chemical change and a Fast change.

Question 2.
Can deforestation be considered a desirable change? Explain.
Answer:

1. Deforestation cannot be considered a desirable change.
2. Because it is harmful to our environment and not desired by us are known as Undesirable changes.

Question 3.
What type of changes is associated with the germination of a seed? Explain.
Answer:

1. Germination of seed is a slow change.
2. Changes which take place over a long period of time (days) are known as Slow changes.

VIII. Answer in detail

Question 1.
Give one example in each case that happens around you.
(a) Slow and fast change
(b) Reversible and irreversible change
(c) Physical and chemical change
(d) Natural and man-made change
(e) Desirable and undesirable change
Answer:

IX. Questions Based on Higher Order Thinking Skills (HOTS)

Question 1.
When a candle is lit the following changes are observed.
Answer:

1. Wax melts.
2. Candle keeps burning.
3. The size of the candle decreases.
4. The molten wax solidifies

Question 2.
Which of the changes can be reversed? Justify your answer.
Answer:
When the candle is burning, the heat of the flame melts the solid wax to liquid wax. This signifies reversible (or) Physical changes. Also, as the wax melts, the size of candle decreases. If then molten wax solidifies and takes a different shape.

Samacheer Kalvi 6th Science Changes Around Us Additional Important Questions and Answers

I. Choose the appropriate answer

Question 1.
Water changes into ice on cooling are called as
(a) Melting
(b) Vaporisation
(c) Condensation
(d) Freezing
Answer:
(d) freezing

Question 2.
_______ is the process in which something becomes different from what it was earlier.
(a) Classification
(b) Composition
(c) Position
(d) Change
Answer:
(d) Change

Question 3.
Evaporation of water from lakes and river
(a) Slow change
(b) Fast change
(c) Natural change
(d) Both (a) and (b)
Answer:
(d) Both (a) and (b)

Question 4.
_______ change is a temporary change
(a) Physical
(b) Chemical
(c) Undesirable
(d) slow
Answer:
(a) Physical

Question 5.
The blackening of the Silver anklet is a (an)
(a) Irreversible change
(b) Temporary change
(c) Short term change
(d) Periodical change
Answer:
(a) Irreversible change

II. Fill in the blanks

1. A change in which a new substance is formed is called ………….
2. Formation of coal is a …………
3. An example of natural as well as an undesirable change is ………..
4. ……… is the Universal Solvent.
5. Eco-friendly changes are ………

Answer:

1. Chemical Change
2. Slow Change
3. Earthquake
4. Water
5. Desirable changes

III. Match the following

Answer
i. – d
ii. – a
iii. – b
iv. – c

IV. Analogy

Question 1.
Rusting of Iron : undesirable change : : Dead plants turn into manure : …………..
Answer:
Desirable change

Question 2.
Touch me not plant: ………… : : digestion of food : Irreversible change
Answer:
Reversible change

Question 3.
Change of seasons : slow change : : Breaking of glass : …………..
Answer:
fast change

Question 4.
Earth quake : undesirable change : : Heartbeat: ………….
Answer:
desirable change

Question 5.
Silver articles turning black : ………… : : Boiling of H₂O : physical change
Answer:
Chemical change

V. Very short answer

Question 1.
What is the change?
Answer:
Change is the observable difference between the initial state and the final state of any substance.

Question 2.
What is a reversible change?
Answer:
Changes which can be reversed (to get back to the original state) are known as reversible changes.

Question 3.
What is melting? Give example.
Answer:
The conversion of a solid into a liquid by heating is called melting. Ex.: Ice into water.

Question 4.
Water is the universal solvent. Why?
Answer:
Water is known as the universal solvent. It dissolves a wide range of substances.

VI. Long answer

Question 1.
Distinguish between the physical and chemical changes.
Answer:

Question 2.
Tabulate some changes taking place in our body system with its type.
Answer:

Students can download 6th Science Term 2 Chapter 1 Heat Questions and Answers, Notes, Samacheer Kalvi 6th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 6th Science Solutions Term 2 Chapter 1 Heat

Samacheer Kalvi 6th Science Heat Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
When an object is heated, the molecules that make up the object
(a) begin to move faster
(b) lose energy
(c) become heavier
(d) become lighter
Answer:
(a) begin to move faster

Question 2.
The unit of heat is
(a) newton
(b) joule
(c) volt
(d) Celsius
Answer:
(b) joule

Question 3.
One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
(a) 80°C
(b) More than 50°C but less than 80°C
(c) 20°C
(d) around 40°C
Answer:
(d) around 40° C

Question 4.
An iron ball at 50°C is dropped in a mug containing water at 50°C. The heat will
(a) flow from iron ball to water.
(b) not flow from iron ball to water or from water to iron ball.
(c) flow from water to iron ball.
(d) increase the temperature of both.
Answer:
(b) not flow from iron ball to water or from water to iron ball.

II. Fill in the Blanks

1. Heat flows from a ……….. body to a ………… body.
2. The hotness of the object is determined by its ………..
3. The SI unit of temperature is …………
4. Solids ……….. on heating and ………… on cooling.
5. Two bodies are said to be in the state of thermal ………… if there is no transfer of heat taking place.

Answer:

1. hot, cold
2. temperature
3. Kelvin
4. expand, contract
5. equilibrium

III. True or False. If False, give the correct answer.

1. Heat is a kind of energy that flows from a hot body to a cold body.
2. Steam is formed when heat is released from water.
3. Thermal expansion is always a nuisance.
4. Borosilicate glass do not expand much on being heated.
5. The unit of heat and temperature are the same.

Answer:

1. True
2. False – Steam is formed when the heat is absorbed from the water.
3. False – Thermal expansion is always not a nuisance.
4. True
5. False – Unit of heat and temperature are different.

IV. Give reasons for the following

Question 1.
An ordinary glass bottle cracks when boiling water is poured into it, but a borosilicate glass bottle does not.
Answer:
The reason is that the borosilicate glass does not expand much on being heated and therefore they do not crack.

Question 2.
The electric wire which sag in summer become straight in winter.
Answer:

1. During summer thermal expansion takes place in electric wire.
2. In winter it contracts so it becomes straight.

Question 3.
Rivet is heated before fixing in the hole to join two metal plates.
Answer:

1. When we heat rivet expansion takes place and becomes soft.
2. One end of the rivet is hammered to form a new head.
3. When cooled, the rivet will contract and hold tightly.

V. Match the following

Answer:
1. – e
2. – c
3. – d
4. – a
5. – b

VI. Analogy

1. Heat: Joule :: Temperature : ………
2. Ice cube : 0°C :: Boiling water : ………..
3. Total Kinetic Energy of molecules: Heat:: Average Kinetic Energy : …………….

Answer:

1. Kelvin
2. 100° C
3. Temperature

VII. Give Very Short Answer:

Question 1.
Make a list of electrical types of equipment at home from which we get heat.
Answer:
Water heater, Iron box, Electric kettle, Micro oven.

Question 2.
What is the temperature?
Answer:
The measurement of the warmness or coldness of a substance is known as its temperature.

Question 3.
What is thermal expansion?
Answer:
The expansion of a substance on heating is called thermal expansion.

Question 4.
What do you understand by thermal equilibrium?
Answer:
When two objects in thermal contact, no longer affect each other’s temperature, there exists Thermal equilibrium.

VIII. Give Short Answer:

Question 1.
What difference do you think heating the solid will make in their molecules?
Answer:

1. When we heat solids the vibrations and movement of molecules will increase.
2. The temperature of the object increases.
3. The distance between molecules will increase.

Question 2.
Distinguish between heat and temperature.
Answer:

IX. Answer in detail:

Question 1.
Explain thermal expansion with suitable examples.
Answer:
Thermal expansion: The expansion of a substance on heating is called, the thermal expansion of that substance.

Fitting the iron rim on the wooden wheel:

1. The diameter of the iron ring is slightly less than that of the wooden wheel.
2. So, it cannot be easily slipped on from the rim of a wooden wheel.
3. The iron ring is, therefore, first heated to a higher temperature so that it expands in size and the hot ring is then easily slipped over to the rim of the wooden wheel.
4. Coldwater is now poured on the iron ring so that it contracts in size and holds the wooden wheel tightly.

Rivetting:

1. Rivets are used to join two steel plates together.
2. Hot rivet is driven through the hole in the plates.
3. One end of the rivet is hammered to form a new rivet head.
4. When cooled, the rivet will contract and hold the two plates tightly together.

Cracking of a thick glass tumbler:

1. Glass is a poor conductor of heat.
2. When hot liquid is poured into the tumbler, the inner surface of the tumbler becomes hot and expands while the outer surface remains at room temperature and does not expand.
3. Due to this unequal expansion, the tumbler cracks.

X. Questions based on Higher Order Thinking Skills

Question 1.
When a window is accidentally left open on a winter night, will you feel uncomfortable because the cold is getting in, or because the heat is escaping from the room?
Answer:

1. When a window is left open on a winter night I will feel uncomfortable because the heat is escaping from the room.
2. The heat will transfer from high temperature to low temperature.
3. During winter cold air enters the room, so room temperature will decrease.

Question 2.
Suppose your normal body temperature was lower than what it is. How would the sensation of hot and cold change?
Answer:

1. When our body temperature is lower than normal temperature, We feel hot from the surrounding.
2. Because the surrounding temperature will be high compare to our body.

Question 3.
If you heat a circular disk with a hole, what change do you expect in the diameter of the hole? Remember that the effect of heating increases the separation between any pair of particles.
Answer:
Many of us “expect” that the diameter of the hole will decrease because the circular disk is free to expand in all directions as well. Note that expansion of metal due to heating is not like gas spreading out wherever space is available. The correct way to think about it is as follows: Hole size is irrelevant in this case. So we can think that hole is very large.

If we carve a hole so large that its radius is slightly less than that of the circular disk itself, then we will have a ring. It is obvious that the radius of the ring will increase, as atoms have more energy so their oscillation amplitude will increase. As the diameter of the ring increases, the diameter of the hole will also increase.

For example, if you want to insert one hallow pipe inside another hollow pipe of the same diameter, just heat anyone and insert the second one into the heated pipe. This explains the answer in an easy way. So it says that diameter will increase with increasing temperature.

Samacheer Kalvi 6th Science Heat Additional Important Questions and Answers

I. Choose the right answer:

Question 1.
When an electric current is passing through the conductor …………… energy is produced.
(a) Electric
(b) Heat
(c) Chemical
(d) Kinetic energy
Answer:
(b) Heat

Question 2.
One day in 1922, the air temperature was measured at 59°C in the shade in Libya ________
(a) America
(b) Africa
(c) Antarctica
(d) Europe
Answer:
(b) Africa

Question 3.
The temperature of boiling water is …………..
(a) 0° C
(b) 32° C
(c) 100° C
(d) 110° C
Answer:
(c) 100°C

Question 4.
The temperature determines the direction flow of _______
(a) heat energy
(b) kinetic energy
(c) potential energy
(d) light energy
Answer:
(a) heat energy

Question 5.
When we cool the liquid it will become …………..
(a) Gas
(b) Solid
(c) Vapour
(d) None
Answer:
(b) Solid

II. Say True or False.

1. Heat is measured in Celsius or centigrade.
2. Temperature in the form of energy.
3. The normal temperature of our body is 37°C.
4. Two objects are said to be in thermal contact if they can exchange heat energy.
5. When the vibrations move from one molecule to another molecule heat will flow.

Answer:

1. False
2. False
3. True
4. True
5. True

III. Match the Following:

Answer
1. – iv
2. – i
3. – ii
4. – v
5. – iii

IV. Analogy

1. Summer : Sag :: Winter : …………
2. Evaporation : 100°C :: Freezing : …………

Answer:

1. contract
2. 0°C

V. Give reasons for the following:

Question 1.
Gaps are left in between rails while laying a railway track.
Answer:
Reason: During summer thermal expansion takes place.

Question 2.
Hot metal ball of 80° C is dipped into water of 80°C. The ball will not contract.
Answer:
Reason: Both are in same temperature.

VI. Very Short Answer:

Question 1.
What are the sources of heat?
Answer:

1. The main source of heat is Sun.
2. Other sources are combustion, friction and electricity.

Question 2.
Define – heat.
Answer:
Heat is an energy that raises the temperature of a thing by causing the molecules in that thing to move faster.

Question 3.
How will you identify two objects are said to be in thermal equilibrium?
Answer:
Two objects in thermal contact have same temperature they are said to be in thermal equilibrium.

Question 4.
What are the measuring unit of temperature?
Answer:
SI unit of temperature is kelvin. Celsius and Fahrenheit are the other units used.

Question 5.
What will determine the direction of flow of heat from one object to another?
Answer:
Temperature will determine the direction of the flow of heat.

VII. Long Answer Questions:

Question 1.
Explain linear expansion with an experiment.
Answer:

1. The expansion in length is called linear expansion.
2. Take a bulb, dry cell, candle, cycle spoke, coin, and two wooden boxes.
3. Place one end of the cycle spoke on a wooden block and connect an electric wire to it. Put a stone over the spoke to hold it.
4. The other one of the cycle spoke is placed on another wooden block.
5. Wrap some electric wire around the coin and place it on the block. Put a stone over the coin to hold it in place.
6. Connect bulb and dry cell to the free ends of wires connected to the coin and the spoke and make the circuit.
7. When we heat the cycle spoke with a candle the length will expand and touches the coin.
8. So the circuit completes, the bulb will glow.
9. When we cool the spoke it contracts and does not touch the coin. So the circuit will disconnect, the bulb will not glow.