9394949438

[LATEST]$type=sticky$show=home$rm=0$va=0$count=4$va=0

NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes

NCERT solutions for class 7 science chapter 6 physical and chemical changes

1. Classify the changes involved in the following processes as physical or chemical changes:

(a) Photosynthesis

Answer:

(a) Photosynthesis is a chemical change.

1. Classify the changes involved in the following processes as physical or chemical changes:

(b) Dissolving sugar in water

Answer:

(b) Dissolving sugar in water is a physical change.

1. Classify the changes involved in the following processes as physical or chemical changes:

(c) Burning of coal

Answer:

(c) Burning of coal is a chemical change.

1. Classify the changes involved in the following processes as physical or chemical changes:

(d) Melting of wax

Answer:

(d) Melting of wax is a physical change.

1. Classify the changes involved in the following processes as physical or chemical changes:

(e) Beating aluminium to make aluminium foil

Answer:

(e) Beating aluminium to make aluminium foil is a physical change.

1. Classify the changes involved in the following processes as physical or chemical changes:

(f ) Digestion of food

Answer:

Digestion of food is a chemical change.

During digestion, enzymes in the stomach and intestines break down food molecules into simpler molecules.

2. State whether the following statements are true or false. In case a statement is false, write the corrected statement in your notebook.

(a) Cutting a log of wood into pieces is a chemical change. (True/False)

(b) Formation of manure from leaves is a physical change. (True/False)

(c) Iron pipes coated with zinc do not get rusted easily. (True/False)

(d) Iron and rust are the same substances. (True/False)

(e) Condensation of steam is not a chemical change. (True/False)

Answer:

(a) False because cutting a log of wood into pieces is a physical change.

(b) False because the formation of manure from leaves is a chemical change.

(c) True.

(d) False because Iron and rust are different substances.

(e) True

3. Fill in the blanks in the following statements:

(a) When carbon dioxide is passed through lime water, it turns milky due to the formation of _________.

(b) The chemical name of baking soda is _________.

(c) Two methods by which rusting of iron can be prevented are _________ and _________.

(d) Changes in which only _________ properties of a substance change are called physical changes.

(e) Changes in which new substances are formed are called _________ changes.

Answer:

(a) When carbon dioxide is passed through lime water, it turns milky due to the formation of calcium carbonate.

(b) The chemical name of baking soda is sodium hydrogen carbonate.

(c) Two methods by which rusting of iron can be prevented are galvanization and painting.

(d) Changes in which only physical properties of a substance change are called physical changes.

(e) Changes in which new substances are formed are called chemical changes.

4. When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.

Answer:

When baking soda is mixed with lemon juice then it is a chemical change, bubbles are formed with the evolution of a carbon dioxide gas.

5. When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.

Answer:

When a candle burns, both physical and chemical changes take place. On heating, candle wax gets melted is a physical change since it again turns into wax on cooling.

The wax gives carbon dioxide, heat, light, water vapour and carbon soot on heating with states chemical change.

Another example is the lightening of the bulb using a dry cell.

6. How would you show that setting of curd is a chemical change?

Answer:

The setting of curd is a chemical change because the new substance(curd) formed from milk differs in taste and it cannot be converted into milk again i.e. it is irreversible.

7. Explain why burning of wood and cutting it into small pieces are considered as two different types of changes.

Answer:

The burning of wood is a chemical change because wood after burning gives carbon dioxide, ash, heat, water vapour also it is an irreversible process.

Whereas cutting wood into small pieces is a physical change because the original composition of wood remains the same and no new substance is formed.

8. Describe how crystals of copper sulphate are prepared.

Answer:

The crystals of copper sulphate are prepared as follows:

1. A cup of water is taken in a beaker.

2. Add some drops of dilute sulphuric acid in it.

3. Heat it and when it starts boiling add copper sulphate powder slowly with continuous stirring.

4. The copper sulphate powder is added till the saturation level.

5. Filter the solution and cool it.

6. Leave it undisturbed and we will observe copper sulphate crystals after some hours.

9. Explain how painting of an iron gate prevents it from rusting.

Answer:

Painting of an iron gate prevents direct contact of iron with water and air(oxygen) which are required for rusting.

No exposure of water and oxygen with iron prevents iron from rusting.

10. Explain why rusting of iron objects is faster in coastal areas than in deserts.

Answer:

Rusting occurs with direct contact of iron with water and oxygen.

In coastal areas,the moisture content is high in the air which states rusting of iron objects is faster in coastal areas because in deserts moisture in the air is absent.

11. The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder it exist as a liquid. When it comes out from the cylinder it becomes a gas (Change – A) then it burns (Change – B). The following statements pertain to these changes. Choose the correct one.

(i) Process – A is a chemical change.

(ii) Process – B is a chemical change.

(iii) Both processes A and B are chemical changes.

(iv) None of these processes is a chemical change.

Answer:

The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder, it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change – A) then it burns (Change – B). This is a chemical change.

Thus, option (ii) is correct.

12. Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.

(i) Process – A is a chemical change.

(ii) Process – B is a chemical change.

(iii) Both processes A and B are chemical changes.

(iv) None of these processes is a chemical change.

Answer:

Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B).

Both process A and B are a chemical change.

Thus, option (iii) is correct.

Chapter No. Chapter Name
Chapter 1 NCERT solutions for class 6 Science Chapter 1 Food: Where Does It Come From?
Chapter 2 NCERT solutions for class 6 Science Chapter 2 Components of Food
Chapter 3 NCERT Solutions for class 6 science chapter 3 Fibre to Fabric
Chapter 4 NCERT Solutions for class 6 science chapter 4 Sorting Materials into Groups
Chapter 5 NCERT Solution for class 6 science chapter 5 Separation of Substances
Chapter 6 NCERT solutions for class 6 science chapter 6 Changes around Us
Chapter 7 NCERT solutions for class 6 science chapter 7 Getting to Know Plants
Chapter 8 NCERT Solutions for class 6 science chapter 8 Body Movements
Chapter 9 NCERT solutions for class 6 science chapter 9 The Living Organisms Characteristics and Habitats
Chapter 10 NCERT Solution for class 6 science chapter 10 Motion and Measurement of Distances
Chapter 11 NCERT solution for class 6 science chapter 11 Light, Shadows, and Reflections
Chapter 12 NCERT solutions for class 6 science chapter 12 Electricity and Circuits
Chapter 13 NCERT solutions for class 6 science chapter 13 Fun with Magnets
Chapter 14 NCERT Solution for class 6 science chapter 14 Water
Chapter 15 NCERT solutions for class 6 Science Chapter 15 Air Around Us
Chapter 16 NCERT Solutions for Class 6 Science Chapter 16 Garbage In, Garbage Out

Study Resources Quick Links

Want to know more

Want to Know More
Please fill in the details below:

INNER POST ADS

Latest IITJEE Articles$type=three$c=3$author=hide$comment=hide$rm=hide$date=hide$snippet=hide

Latest NEET Articles$type=three$c=3$author=hide$comment=hide$rm=hide$date=hide$snippet=hide

Name

Admissions,1,Alternating Current,60,AP EAMCET 2020,1,Basic Maths,2,BCECE 2020,1,best books for iit jee,2,best coaching institute for iit,1,best coaching institute for iit jee preparation,1,best iit jee coaching delhi,1,best iit jee coaching in delhi,2,best study material for iit jee,4,BITSAT Registration 2020,1,Blog,62,books for jee preparation,1,books recommended by iit toppers,3,Capacitance,3,CBSE,1,CBSE accounts exam,1,CBSE boards,1,CBSE NEET,9,cbse neet 2019,3,CBSE NEET 2020,1,cbse neet nic,1,Centre of Mass,2,Chemistry,58,Class 12 Physics,15,coaching for jee advanced,1,coaching institute for iit jee,2,Collision,2,COMEDK UGET 2020 Application Form,1,COMEDK UGET 2020 Exam Form,1,COMEDK UGET news,1,CUCET 2020,2,Current Electricity,4,CVR college,1,Electromagnetic Induction,3,Electronics,1,Electrostatics,3,Energy,1,Fluid Mechanics,4,Gravitation,2,GUJCET 2020 Application Form,1,Heat,4,iit admission,1,iit advanced,1,iit coaching centre,3,iit coaching centre in delhi,2,iit coaching classes,2,iit coaching in delhi,1,iit coaching institute in delhi,1,iit entrance exam,1,iit entrance exam syllabus,2,iit exam pattern,2,iit jee,5,iit jee 2019,3,iit jee advanced,2,iit jee books,3,iit jee coaching,2,iit jee exam,3,iit jee exam 2019,1,iit jee exam pattern,3,iit jee institute,1,iit jee main 2019,2,iit jee mains,3,iit jee mains syllabus,2,iit jee material,1,iit jee online test,3,iit jee practice test,3,iit jee preparation,6,iit jee preparation in delhi,2,iit jee preparation time,1,iit jee preparation tips by toppers,2,iit jee question paper,1,iit jee study material,3,iit jee study materials,2,iit jee syllabus,2,iit jee syllabus 2019,2,iit jee test,3,iit preparation,2,iit preparation books,5,iit preparation time table,2,iit preparation tips,2,iit syllabus,2,iit test series,3,IITJEE,100,IPU CET,1,JEE Advanced,83,jee advanced exam,2,jee advanced exam pattern,1,jee advanced paper,1,JEE Books,1,JEE Coaching Delhi,3,jee exam,3,jee exam 2019,6,JEE Exam Pattern,2,jee exam pattern 2019,1,jee exam preparation,1,JEE Main,85,jee main 2019,4,JEE Main 2020,1,JEE Main 2020 Application Form,2,JEE Main 2020 news,2,JEE Main 2020 Official Answer Key,1,JEE Main 2020 Registration,1,JEE Main 2020 Score,1,JEE Main application form,1,jee main coaching,1,JEE Main eligibility criteria,3,jee main exam,1,jee main exam 2019,3,jee main online question paper,1,jee main online test,3,JEE Main Paper-2 Result,1,jee main registration,2,jee main syllabus,2,JEE mains 2020,1,jee mains question bank,1,jee mains test papers,3,JEE Mock Test,2,jee notes,1,jee past papers,1,JEE Preparation,2,jee preparation in delhi,1,jee preparation material,4,JEE Study Material,1,jee syllabus,6,JEE Syllabus Chemistry,1,JEE Syllabus Maths,1,JEE Syllabus Physics,1,jee test series,3,KCET - 2020,1,Kinematics,1,Latest article,5,Latest Articles,61,Latest News,34,latest news about neet exam,1,Laws of Motion,2,Magnetic Effect of Current,3,Magnetism,3,MHT CET 2020,2,MHT CET 2020 exam schedule,1,Modern Physics,1,NCERT Solutions,15,neet,3,neet 2019,1,neet 2019 eligibility criteria,1,neet 2019 exam date,2,neet 2019 test series,2,NEET 2020,2,NEET 2020 Application Form,1,NEET 2020 Eligibility Criteria,1,NEET 2020 Registration,1,neet application form,1,neet application form 2019 last date,1,Neet Biology Syllabus,1,Neet Books,3,neet eligibility criteria,3,neet exam 2019,7,neet exam application,1,neet exam date,1,neet exam details,1,neet exam pattern,6,neet exam pattern 2019,2,neet examination,1,neet mock test 2019,1,Neet Notes,3,Neet Online Application Form,3,neet online test,2,neet past papers,1,neet physics syllabus,1,neet practice test,2,NEET preparation books,1,neet qualification marks,1,NEET question paper 2019,1,neet question papers,1,neet registration,1,Neet Study Material,3,neet syllabus,6,neet syllabus 2019,5,NEET Syllabus 2020,1,neet syllabus chemistry,1,neet syllabus for biology,1,neet syllabus for physics,1,neet test series,1,neet ug 2019,2,news,5,online study material for iit jee,1,Optical Instruments,1,Physics,110,physics books for iit jee,1,Power,1,Practical Physics,1,Quiz,5,Ray Optics,1,Rotational Motion,3,SHM,3,Simple Harmonic Motion,3,study materials for iit jee,1,Study Notes,110,study notes for iit jee,1,Thermodynamics,4,TS EAMCET Notification,2,Units and Dimensions,1,UPSEE 2020,1,UPSEE 2020 Application Form,2,UPSEE EXAM,1,Vectors,2,VITEE Application form,1,Wave Motion,3,Wave Optics,1,WBJEE 2020 Admit Card,1,WBJEE 2020 Answer Key,1,Work,1,
ltr
item
Best IIT JEE Coaching Institute in Delhi | NEET Coaching Institute in Delhi: Class 7 Science Chapter 6 Physical and Chemical Changes
Class 7 Science Chapter 6 Physical and Chemical Changes
https://1.bp.blogspot.com/-1AP8-onF2VU/X2xyvKyo8eI/AAAAAAAAATU/EQPgaitvSBk2a9oYdRZXN0YofcuCe2x3QCNcBGAsYHQ/s320/Cleariitmedical%2BAcademic%2BTemplate%2BImage.pptx%2B%25285%2529%2B%25281%2529.jpg
https://1.bp.blogspot.com/-1AP8-onF2VU/X2xyvKyo8eI/AAAAAAAAATU/EQPgaitvSBk2a9oYdRZXN0YofcuCe2x3QCNcBGAsYHQ/s72-c/Cleariitmedical%2BAcademic%2BTemplate%2BImage.pptx%2B%25285%2529%2B%25281%2529.jpg
Best IIT JEE Coaching Institute in Delhi | NEET Coaching Institute in Delhi
https://www.cleariitmedical.com/2020/09/NCERT-Solutions-for-Class-7-Science-Chapter-6-Physical-and-Chemical-Changes.html
https://www.cleariitmedical.com/
https://www.cleariitmedical.com/
https://www.cleariitmedical.com/2020/09/NCERT-Solutions-for-Class-7-Science-Chapter-6-Physical-and-Chemical-Changes.html
true
7783647550433378923
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS CONTENT IS PREMIUM Please share to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy