NCERT Solutions Class 6 Science Changes Around us

Scroll down to download pdf file

NCERT Solutions for Class 6 Science for chapter 6 Changes Around us

Question.1 

To walk through a water logged area, you usually shorten the length of your dress by folding it. Can this change be reversed?

Answer.

Yes, the length of dress can again be increased by unfolding it. Therefore, it is a reversible change.

Question.2

You accidentally dropped your favourite toy and broke it. This is change you did not want. Can this change be reversed?

Answer.

No, this change cannot be reversed.

Question.3

Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not. 

S.No.

Change

Can be reversed(Yes/No)

1.

The sawing of a piece of wood

 

2.

The melting of ice candy

 

3.

Dissolving sugar in water

 

4.

The cooking of food

 

5.

The ripening of a mango

 

6.

Souring of milk

 

Answer. 

S.No.

Change

Can be reversed(Yes/No)

1.

The sawing of piece of wood

No

2.

The melting of ice candy

Yes

3.

Dissolving sugar in water

Yes

4.

The cooking of food

No

5.

The ripening of a mango

No

6.

Souring of milk

No

Question.4

A drawing sheet changes when you draw a picture on it. Can you reverse this change?

Answer.

If we draw a picture on a drawing sheet with a pencil, then the picture can be erased with an eraser. Therefore, we can get back the original drawing sheet. If we draw a picture on a drawing sheet with a pen, then the original drawing sheet cannot be obtained as we cannot erase ink.

Question.5

Give examples to explain the differences between changes that can or cannot be reversed.

Answer.

1. Formation of curd from milk is an irreversible change as a new product (curd) is formed. Neither any bacteria nor any change in conditions can convert curd back into milk.

2. Take a piece of paper and fold it to make a toy aeroplan We can get back the original piece of paper by unfolding it. Take the same piece of paper and draw an aeroplane on it, cut along its outline. In this condition we cannot get back the original piece of paper as pieces of paper cannot be rejoined.

3. Take some dough and make a ball. Try to roll out a chapati. After we roll out a chapati from a ball of dough, the chapati can be converted back to ball. Once we cook the chapati, it 
cannot be converted back to ball.

Question.6

A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?

Answer.

No, the change in POP cannot be reversed. Plaster of Paris (POP) has a property of setting into a hard mass on wetting with water due to the formation of a new compound called gypsum. Once the POP is hardened, it cannot be converted back into POP. Hence, it is an irreversible change.

Question.7

A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?

Answer.

Cement sets into a hard mass on mixing with water. The hard mass obtained cannot be converted back to cement. Therefore, It is essential to keep cement away from rain otherwise it will change into a hard mass which is of no use.

Tags: 

Click on the text For more study material for Science please click here - Science

Latest CBSE News

  • In continuation of the efforts of the government to standardize the education system across the country, government has decided to implement NCERT curriculum system in Tripura also. The education minister of Tripura announced that from next academic year which is starting from 1st April, NCERT (National Council for Educational Research and Training) will be applicable in all schools in Tripura....
  • CBSE has released the following FAQs for Class 11 Academic Session 2018-19 for Computer Science and Informatics Practices - New Syllabus Frequently Asked Questions (FAQs) Class XI (Academic Session 2018-19) Informatics Practices (New Syllabus) 1. Which version of Python should be preferred? Ans: Version 3.x. Preferably 3.6.4 and above.  2. From where Python can be downloaded? Ans: Python Language...
  • NCERT is an organization which was formed by the Government of India in 1961. The organisation was formed by merging atleast seven government education institutions. The NCERT was formed to standardize the education system in India. The main objective was to publish high quality NCERT books which can be implemented in the entire country to ensure standard education system across the country....
  • NCERT is a government organisation which has been set up to advise the central and state governments on various Matters relating to academics which are related to elementary and Senior school education level. The overall objective of setting up this department was to improve the education level in the entire country. The objective of this department was to prepare and publish text books as per...
  • What is NTSE Exam ? National Talent Search Examination which is called NTSE in short is a national level examination which is conducted by NCERT (National Council of Education Research and Training). This is one of the most prestigious national level scholarship based exam conducted in India. This is also one of the oldest exam conducted at a national level in India. The first exam was conducted...
  • Government has been working on revamping the school level education system for all CBSE affiliated schools in India. HRD ministry has recently asked for suggestions from teachers, students and parents on the syllabus contents. Thousands of respondents along with teachers submitted their responses on the MHRD website on their opinion about the syllabus for various classes and what all topics to...
  • CBSE has issued a circular to students and various schools to increase awareness amongst students regarding careful disposal of e-waste. CBSE has issued a letter from Ministry of Ministry of Electronics & Information Technology (MeitY),Govt. of India regarding increasing awareness programme on Environmental Hazards of Electronic Waste amongst students. The schools have been advised to tell...