NCERT Solutions for Class 6 Science Chapter 6 provides knowledge on topics related to Changes Around Us. The detailed answers in this NCERT solution resource will help you to fully understand the concept. By studying this chapter, you will be able to get good grades on the 6th grade exam.
1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Ans: Yes, it can be reversed by unfolding the dress.
2. You accidentally dropped your favourite toy and broke it. This is a change you did not want. Can this change be reversed?
Ans: No, this change (breaking of toy) cannot be reversed.
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.
4. A drawing sheet changes when you draw a picture on it. Can you reverse this change?
Ans: No, we cannot get fresh drawing sheet once a picture is drawn on it with paint/ oil or water. However, we can reverse the change, if soft pencil is used to draw the picture.
5. Give examples to explain the difference between changes that can or cannot be reversed.
Ans: Examples of reversible and irreversible changes
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?
Ans: No, the change in POP cannot be reversed since it is a chemical change.
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?
Ans. No, these are irreversible chemical changes.
1. What is a physical change? Explain with example.
Ans: The changes in which only physical properties of substances are changed and no new substance is formed is called physical change. It is a reversible change. Example: Boiling and freezing of water.
2. What is a chemical change? Explain with example.
Ans: The changes in which new substance with new chemical properties are formed are called chemical changes.
Example: Reaction between washing soda and lemon juice in which C02 and other substances are formed.
3. What happens when sugar is heated?
Ans: When sugar is heated continuously then a black powdery substance is formed. This is a chemical change.
1. Explain how a metal rim slightly smaller than a wooden wheel can be fixed on it.
Ans: The metal rim is always made slightly smaller than the wooden wheel. The metal rim is heated. On heating, the rim expands and fit onto the wheel. Cold water is then poured over the rim. Due to cooling the metal rim contracts and fits tightly onto the wheel.
2. How does curd being set? Is this change reversible?
Ans: A small quantity of curd is added to warm milk. The milk is stirred and is set aside undisturbed for a few hours at a warm place. In a few hours, the milk changes into curd.
Curd formed from milk cannot be changed into milk again. So, this an irreversible (cannot be reversed) change.
Exercise Questions
1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Solution:
Yes, the process can be reversed.
2. You accidentally dropped your favorite toy and broke it. This is a change you did not want. Can this change be reversed?
Solution:
No, this change cannot be reversed
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.
| Sl 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 |
Solution :
| Sl No | Change | Can be reversed Yes/No |
| 1 | The sawing of a 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 |
4. A drawing sheet changes when you draw a picture on it. Can you reverse this change?
Solution:
This change can be reversed if a pencil is used to draw the picture. If a pen or colors are used to draw the picture, change cannot be reversed.
5. Give examples to explain the difference between changes that can or cannot be reversed.
Solution:
Changes that can be reversed
i) Opening and closing the door
ii) Filling glass with water
Changes that cannot be reversed
i) Conversion of milk into curd
ii) Ripening of fruit
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 immobilized. Can the change in POP be reversed?
Solution:
No, the change cannot be reversed
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?
Solution: No, the change cannot be reversed
There are about four questions in Chapter 6 of Grade 6 NCERT Science Answers. Students who cannot answer the textbook questions are advised to Download Free PDF From Stromlap.in The solution is created according to the latest CBSE syllabus and guidelines so that students can pass the exam without fear. Daily use of the solution allows students to answer complex questions that arise during the exam. Professional faculty design solutions aimed at helping students succeed in their annual exams
Follow Me on Social Media Platforms for Your Feedback & Doubts
Mechanical systems are used in a wide range of industries and applications, from manufacturing and…
Online shopping has become a popular trend, and it is now easier than ever to…
Technology has become an integral part of our lives, and it continues to shape the…
Working from home has become increasingly popular in recent years, and with the pandemic, it…
Physics has always been a field that has relied heavily on technology to push the…
In today's digital age, children are growing up with technology all around them. Smartphones, tablets,…