Changes Around Us - Class 6 Chemistry - Extra Questions

Folding paper to make an aeroplane is a reversible change. Why?



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?



Give two examples of irreversible changes.



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



Explain how a metal rim slightly smaller than a wooden wheel can be fixed on it.



In places of hot climate, it is advised that the outer walls of houses be painted white. Explain.



Can you say deforestation is an irreversible or reversible change?



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



Some common changes are given in the table. Which of these changes do you think can be reversed?
Change
Can be reversed
(i) Raw egg to boiled egg
Yes/No
(ii) Batter to idli

(iii) Wet clothes to dry clothes

(iv) Woolen yarn to a knitted sweater

(v) Grain to its flour

(vi) Cold milk to hot milk

(vii) Straight string to a coiled string

(viii) Bud to flower

(ix) Milk to paneer

(x) Cow dung to biogas

(xi) Stretched rubber band to its normal size

(xii) Melting of ice-cream



Give two examples of reversible changes.



How does curd made? Is this change reversible?



Give one example of a change which occurs on heating but cannot be reversed.



A change in which the substance can be brought back to its original state is called a _____________ change.



Are all the changes taking place in substances permanent, temporary or reversible? 



A piece of iron is heated until it becomes red-hot. It then becomes soft and is beaten to a desired shape. What kinds of changes are observed in this process reversible or irreversible?



Give reasons:
Dissolving salt in water is a reversible change.



Name any two changes under which the stretching of spring can be classified as?



The substances cannot get back into their original form in a .................. change.



Conversion of liquid to vapors is a ...............change.



Conversion of water into vapour, which type of change is this? Temporary or permanent?



Define temporary change.



Explain reversible and irreversible changes giving examples.



Class 6 Chemistry Extra Questions